7,56 


THE  LIBRARY 

OF 

THE  UNIVERSITY 
OF  CALIFORNIA 

LOS  ANGELES 


UTLINES    OF 
ASTRONOMY 


In  Graham*  s 
Standard  Phonography 


CONTENTS 


The  Figure  of  the  Earth  . 

The  Motion  of  the  Earth  .'' 

The  Moon       ....  V 

The  Sun    .....  ». 


PARAGRAPH 

3 

4 
5 
6 


The  Planets    ......      7 

Mercury  i      .      .      9 

Venus  .....  .  .      .     .10 

The  Earth       ......    1  1 

Mars     ........    12 

The  Asteroids  ......    13 

Jupiter  ........    14 

Saturn  ........    15 

Uranus       .......    16 

Neptune     .......    17 

Comets       .......   21 

Day  and  Night      .....   23 

The  Figure  of  the  Earth's  Orbit 
Explanatory  of  the  Variations 
of  Day  and  Night     ...    25 
Phases  or  Changes  of  the  Moon  26 
Eclipses       .......   27 

Eclipses  of  the  Satellites  .      .      .28 
Tides    ......      .      .   29 


PARAGRAPH 

Cause  of  the  Tides  .  .  .  .31 

The  Zodiac 32 

Divisions  of  the  Celestial  Sphere  3  3 
Signs  of  the  Zodiac  ...  34 

The  Seasons 35 

Causes  of  the  Variations  of 

Temperature  .  .  .  .36 
General  Divisions  of  Time  .  .  40 

Sidereal  Time 41 

Solar  Time 42 

Cause  of  the  Difference  of  Time 

in  Different    Parts  of  the 

World 43 

The  Calendar 44 

Origin  of  the  Names  of  the 

Month 45 

Origin  of  the  Names  of  the  Days  46 
The  Sidereal  System  ...  47 

The  Fixed  Stars 48 

Binary  Stars 49 

The  Constellations  ....  50 
The  Milky  Way  .  .  .  .51 
The  Nebulae 52 


NEW  YORK: 
ANDREW  J.  GRAHAiM  &  CO. 


THE  WINTHROP  PRESS,    NEW  YORK 


OUTLINES 
OF  ASTRONOMY 


IN  THE  ADVANCED 

REPORTING   STYLE 


OF 


GRAHAM'S 
STANDARD  PHONOGRAPHY 


NEW  YORK 

ANDREW  J.  GRAHAM  &  CO. 
744  BROADWAY 


Copyright,  1899,  by  ANDREW  J.  GRAHAM  &  Co. 


OUTLINES  OF  ASTRONOMY. 


PREFACE. 


I         I 

,x  /^^   o   C  / 

vV-'      -W--V-/ 

>       N- 

~ 

i.    DESCRIPTIVE  SKETCH. 
•  -v        U  /^     — ^ 

I       ,.  >r        -^/-X-'     •->«- 

.^_  —  ..c. ,  -.Ci^/Cp;.^ -X  '- 

i  -•\aci-yj  J.-A  -   -— -  '--v^-  -  -^ 

x."""  i^. 

^1 

o,^      I  ^ 


449550 


OUTLINES  OF  ASTRONOMY. 


^~ 

V 

3.    '  ^= -\  I     *"£  .-TV.,    ^~X>  -~^  ^ 

D  Vb 

/  I                ;!- 
1 /--p 

"^yv^.t/ 

^V- 

^     v  ^ — i 

_./x_-l  O  ??--/ 
V^/  j> 

v.---~-^^-^ 

n  c^:.  [p|  C  xfS^A.t;  ^ 

--^ 

__      _      /  _/ 1       &     xiy     v^, 

^ 


OUTLINES  OF  ASTRONOMY. 


O  UT  LINES  OF  A  .9  TRONOM  Y. 


\ 

• 


J  — 


•\>  .rv*.  _v 


,  _..x 

r          c 


,  I  L    '  S  ^-/  ^ 


r  1    ^_- 
-£-=>-  '  -  -  - 

vo  (-  -^V_^-  - 


OUTLINES  OF  ASTRONOMY. 


--^        -- 


M  c_    /.m -.-v  - 


OUTLINES  OF  ASTRONOMY, 


^-  -\^;  *: "  "H  •"'-"  r 

->'^~--^--—  ^v---^- 

^^       «\  /  /  /'          V-V 

\x    /7  jff*^/  ,  o-x  r   ^-      v^- 

'V-^  -  --y    \- 


x 


.  L 


OUTLINES  OF  ASTRONOMY, 


_,_    A     _     Q    _       _     <J-fc 


II. 


t  O       1 

"  /  ^T  ~  _/      ^  ,^~    -1  •* 

----'7' / «— *  --\ 


OUTLIXES  OF  ASTRONOMY. 


OUTLINES  OF  ASTROXOMY. 


OUTLINES  OF  ASTRONOMY. 


^n 


<.3 

/ 

V 


<^_. 
Pv. 


r 


^: 


«.^_ 


OUTLINES  OF  ASTRONOMY. 


//. 


L  X-J^- 


- 


-- 


--/^-t 


OUTLINES  OF  ASTRONOMY. 


~  £     •' 

•le-"-^ 

V 


OUTLINES  OF  ASTRONOMY.  15 


X    f  v   Lf-—*/        fjo___    ^/__, 

—x 

£•    X-" 

50   " 

•xA.^. 

\-—t 

r^Sy—T^ 

^.c.rvs 


.- 
V 


i6 


VUTUNES  OF  ASTRONOMl. 


Zl     -- 


7 


V 


-.  — -N  -x   c 

._  -— - 


ti. 


V 


-\rv"1l^> 


r 


OUTLINES  OF  ASTRONOMY. 


22 


^^ 


Lr/:. 


o/-    T      -^       ^ 


OUTLINES  OF  ASTRONOMY. 


. 

f 


L 


"fS 


/ 

/.l-V  ..-Jj^^at/. 

^v    •>  7 


-~> 


^L 


l  • 


° 


j 


.v 
\ 


^_p 


r±l. 


OUTLINES  OF  ASTRONOMY, 


19 


y  *  *~s.  ~^  ^  i_y 

_Y7__"  x( 
-^-(--Jr^rl 

-^—  M— V^-r-  ™- «--  -    -V^-  ^-  -  --„-/--' -« ' 

i  *m    - , ^  ^ 

i^rk-^v^ 

'_r^rr._.'_D— _.*X._wc :— V?— 

- 


OUTLINES  OF  ASTRONOMY. 


/     J        »  I        /     C-_     ^ ^ 

/-^-^-AOU/' 

J27    ^ 

*> 

° 

B ,  ^ 

L^r/r 

>- 

X 

^  * 

^__  \  c/*  \_~-iA 

+.*^-T^.^^2*  *^?£'\~ 

^  r^-^.J^^      __l  ...^.AxC     _^^. 

^  S  / 

_<V!_^/__^  .V->   c   VV^T.JL  3  4J^  V-.'U^ 

*•  / 

*•*'  •     J-V  <^;  — ----- ^y-- ^/ 
X   m   x<~  \       "i.  s.  l:      -p/^o 

• 


OUTLINES  OF  ASTRONOMY. 


30 


A*—  x 

.-N-'   '- 


~   , 


JTLj..x.!x 


E 


z+.-.-yl.^  «._^9. 
•r/       ' 


->-  r^ 


•  -V- 


22 


OUTLINES  OI>  ASTRONOMY 


U- ..\ ^-^- v- -*,*-     ""     V ^-^ _W I  " " 

t 

i__<?__\  P-.VS^-^--^/^  ^.^.AJ 
J  I '', 

-v/7      J    <>v  /  /i    * 

X 

flv 

1 
_v  r\---±L 

±±-.-r.  ^..L..^rC_X--  — '--/ 

^^VV^^^.^^/C^.V  /M. 

Q 7  /I  *^  /(*  Y  * — 

I         /"    \  /     .  *  *  *  ^^ — •*        -    • 

35.  i_  Q— x-:.^ 


OUTLINES  OF  ASTRONOMY, 


f~       *\    °'  ~\         L 

_  e  .!~r! 
r?^ 

/.^.c:^.r    .      s../....c 

f    '  ^    V 

<L_r=rs^c?-     «j <r->-N ,  .-•>.--.- -^-P--  i —    V-f-- 

*  ^N,  ~V-^    ^»>-x-  V 

5=v.i_.^J.i/:  ^U^9-rr^4^V- 

k^-:-x^-  /^.i-^-.-.^^---^^.^.-.'.^^ 

:-y-c--  -  vf^-  -  -  -^  -  ^-  -  -  ->^v^ 

,/--.>_-:_w/:X^ 

.     .     Qj>/  .    .         QL*  \  r, 

o-5     _      .  _  J V* — ^ 


24 


OUTLINES  OF  ASTRONOMY. 


^TT  ' 

X-  «  >.."? 


/__v£> 


•c 


j.^o  ).:t>..*d 


e-  -x- 

-.vT.-}  «. '(  /.I  A.    \_ ^ 

X    ^~? 

?' 


r*s 


»t*~~*s4 


j 


<»: 


^ 


~ • 


OUTLINES  OF  ASTRONOMY. 


,~^.-t-v 


--     _ 


:  r 


• 

..I 


26 


OUTLINES  OF  ASTRONOMY, 


OUTLINES  OF  ASTRONOMY. 


•x 


I  V,_»  CT 


V     V 


28 


OUTLINES  OF  ASTRONOMY, 


^__... 

—  ^^     I 


-v 


OUTLINES  OF  ASTRONOMY. 


29 


v. 


>-V- 


3° 


OUTLINES  OF  ASTRONOMY. 


c\ 

'•-'-— t>J 


I'VX. 


./( 


O UTLIXES  OF  AS TRONOM ) '. 


-^  v  I          I  -S  (, 

*  4^----/^--Ns— ^j 

"^v/y-V- 

/i  / 

JtV.  _r\.T\^  ^.C-^./K.:.-^  KJ/ 

fcr7 

''MS     ^         I  /' 

4t> !><>/ v— 

/ 
/          -^     £~^ 

^ 

"SLs 

3T^^..-**/.~*  ^^/_...!4^ 

""^0""  '      L~n~/    A^I^~ 

I  V~  * 

w    -  %"^ 

.^.-..^.U       -    i         '  —-  ^  ^      ^ 

X..-X- 


OUTLINES  OF  ASTRONOMY. 


-> 


W— < 


7 


,% 


i    y 


OUTLINES  OF  ASTRONOMY. 


33 


o- 


\ 


34 


OUTLINES  OF  ASTRONOMV. 


si    :.... IT.. 

/    ^  b 

Zo_v 
xf 

r> 
l>^-/       •>- 

-,  V—  1}^-^-^-^}^-  v-f" 

N  ^  *N^ 

c -"  n: )_c^_ _^>  /__•__" A    7-^.. j x /j_"_ 

\*  "Cy*^ "  "^~      "^S" ""    1  " " "/"        ""** 
--t" 
5^  :--~rs 


OUTLINES  OF  ASTRONOMY. 


;r.\  /_ 


^V^— =v/— -"—- 


•-y-i-jsz-v-t--- M 


OUTLINES  OF  ASTRONOMY. 


-H 


r._S:S.,.>u 


^ 


OUTLINES  OF  ASTRONOMY. 


37 


449550 


OUTLINES  OF  ASTRONOMY. 


BY   A   MEMBER   OF   THE   ENGLISH    PHONETIC   SOCIETY 


From  The  Standard-Phonographic  Visitor. 


PREFACE. 

These  "  Outlines  "  have  been  composed  more  especially  for  the 
use  of  those  whose  early  education  has  been  neglected.  Purely 
scientific  technicalities  have  therefore  been  rejected,  so  far  as 
was  compatible  with  perspicuity  and  conciseness. 

Astronomy  is  one  of  the  most  useful  and  entertaining  among 
the  whole  range  of  the  strictly  physical  sciences,  and  is  admir- 
ably adapted  to  expand  the  intellectual  faculties  ;  and,  indirectly, 
to  exalt  the  moral  affections.  Under  this  conviction  this  little 
treatise  has  been  prepared,  and  the  earnest  wish  of  the  author  is, 
that  it  may  accomplish  its  intended  purpose. 

I.      DESCRIPTIVE   SKETCH. 

1.  Astronomy  is  a  term  employed  to  designate  the  science  of 
the  material  heavens.     Being  compounded  of  two  Greek  words, 
astron,  a  star,  and  nomos,  a  law,  it  signifies,  literally,  the  law  of 
the  stars.     While  imparting  a  knowledge  of  those  glittering  orbs 
which  spangle  the  heavens,  it  at  the  same  time  explains  many 
of  the  most  important  physical  phenomena  connected  with  our 
earth.     Some  of  these  will  be  exhibited  in  the  following  pages.* 

2.  In  nothing  perhaps  is  the  human  mind  more  liable  to  de- 
ception, if  its  judgments  be  formed  from  appearances  only,  than 
in  its  estimation  of  those  subjects  which  come  properly  within 
the  sphere  of  astronomical  science.    To  the  uninformed  observer, 
the  earth  upon  which  he  dwells  appears  as  a  comparatively  flat 
surface,  or  level  plain,  and  also  as  a  solid  and  immovable  mass 
of  matter.     He  looks  upwards  toward  the  magnificent  ethereal 
expanse  bespread  around,  and  it  appears  as  though  the  whole 


OUTLINES  OF  ASTRONOMY.  39 

firmament,  with  its  celestrial  scenery,  were  continuously  passing 
over  his  head,  at  no  great  distance  from  him.  The  starry  hosts, 
too,  seem  to  be  no  more  than  mere  specks  of  luminous  matter  or 
small  jets  of  light.  Scientific  discovery,  however,  dissipates  the 
illusion  and  bears  ample  testimony  that  these  first  impressions 
are  erroneous  ;  and  it  is  the  province  of  astronomy  to  rectify 
them  and  to  present  a  more  enlightened  and  philosophical  con- 
ception of  the  universe. 

3.  The  Figure  of  the  Earth.  We  make  this  our  starting  point 
in  a  description  of  the  heavens,  because  the  earth  being  itself 
one  of  the  heavenly  bodies,  and,  in  relation  to  ourselves,  perhaps 
the  most  important  one,  a  right  knowledge  of  it  will  greatly 
facilitate  a  comprehension  of  the  others.  It  has  been  dem- 
onstrated with  mathematical  certainty  that  the  earth  is  not  a 
plane  surface  but  a  globe/  and  that  so  far  from  its  being  sta- 
tionary, it  is  incessantly  moving.  Its  figure  is  not,  however, 
completely  spherical,  but  approaches  more  to  the  spheroidal 
form,  or,  as  some  have  termed  it,  an  oblate  spheroid,  that  is, 
very  much  resembling  the  shape  of  an  orange,  having  its  ex- 
tremities flattened.  Notwithstanding  the  unevenness  and  irreg- 
ularities of  its  surface,  arising  from  alternate  elevations  and 
depressions,  it  is  still  spherical,  for  these,  in  comparison  with  its 
magnitude,  induce  no  greater  divisions  from  the  globular  form 
than  the  minute  indentations  upon  the  rind  of  an  orange.  For 
all  practical  purposes  then  the  earth  may  be  regarded  as  a  globe. 
Rational  arguments  for  its  rotundity  may  be  derived  from  the 
fact  of  several  eminent  nautical  men,  among  whom  was  Captain 
Cook,  having  sailed  completely  round  it.  Traversing  on  and 
on,  over  the  bosom  of  the  deep,  always  bearing  to  the  west,  they 
have  ultimately  arrived  at  the  spot  from  which  they  started.  It 
is  known  also  from  this  circumstance,  that  when  a  vessel  out  at 
sea  is  bearing  towards  us.  the  first  point  observable  above  the 
horizon  is  the  top  of  its  masts  ;  as  it  approaches  the  lower  por- 
tions gradually  become  visible,  until  at  last  we  perceive  the  full 
outline  of  the  ship.  Were  the  earth  a  level  plane  such  could  not 
be  the  case,  for  upon  so  smooth  a  surface  as  the  ocean,  when  one 
portion  appeared  the  whole  would  at  the  same  time  be  visible, 
diminished  of  course  in  proportion  to  the  distance.  The  glob- 


40  OUTLINES  OF  ASTRONOMY. 

ularity  of  the  earth's  figure  receives  collateral  illustration  from 
that  of  the  other  heavenly  bodies,  for  it  is  a  law  pervading  nature 
that  similar  things  shall  mutually  illustrate  each  other;  hence, 
while  an  astronomical  knowledge  of  our  globe  will  enable  us  to 
understand  certain  particulars  relating  to  other  members  of  the 
solar  system,  they  reciprocally  furnish  us  with  instruction  con- 
cerning it.  The  aspect  of  the  planets,  seen  through  a  telescope, 
is  spherical,  but  independently  of  this  the  phenomenon  of  eclipses 
is  quite  sufficient  to  establish  the  fact,  for  the  earth's  shadow 
reflected  upon  the  moon  is  always  perceived  to  be  round,  as  is 
also  the  moon's  shadow  cast  upon  the  sun.  A  shadow  always 
presents  a  faithful  outline  of  the  body  from  which  it  is  projected. 
4.  The  Motion  of  the  Earth.  It  was  remarked  above  (paragraph  3) 
that  the  earth  is  constantly  moving.  This  follows  almost  as 
a  consequence  of  its  figure.  Conceive  of  it  as  a  globe  poised  in 
space  and  it  is  difficult  to  imagine  how  it  could  be  exempted 
from  mobility.  The  ethereal  vault  in  which  it  is  suspended  is 
composed  of  elements  so  subtle  and  refined  as  to  be  destitute  of 
any  buoyant  power  sufficient  to  support  the  inert  mass,  where- 
fore motion  becomes  a  necessity  of  its  existence;  but  this  simple 
fact  is  not  adequate  to  the  solution  of  the  precision  and  reg- 
ularity observable  in  all  its  movements.  These  can  be  attributed 
only  to  the  agency  of  certain  fixed  laws  impressed  on  the  original 
constitution  of  things  by  the  Divine  Creator.  It  is  found  by 
careful  observation,  assisted  by  ingeniously  constructed  instru- 
ments and  other  appliances,  that  the  earth  rotates  upon  its  center 
as  a  revolving  globe  upon  an  axle,  and  with  amazing  swiftness, 
maintaining  a  perpetual  whirl.  In  addition  it  is  found  that  the 
sun,  notwithstanding  the  appearance  to  the  contrary,  stands  in 
relation  to  the  earth  as  a  fixed  body.  Although  in  reality  it  is 
not  free  from  motion,  yet  it  maintains  the  same  general  position 
in  reference  to  this  globe.  In  consequence  of  the  relative  im- 
mobility of  the  sun's  position,  the  earth  is  the  subject  of  a  sec- 
ondary, which  is  a  progressive  motion  round  the  central  lumin- 
ary. Its  primary  or  axillary  movement  is  called  its  diurnal 
motion,  because  it  is  completed  in  the  space  of  a  day  ;  the  sec- 
ondary or  progressive  motion  is  called  its  annual  revolution, 
because  its  circuit  is  accomplished  in  the  space  of  a  year.  These 


OUTLINES  OF  ASTRONOMY.  41 

combined  movements,  which  are  unceasing,  produce  the  com- 
mon illusion  that  the  earth  is  a  central  body,  about  which  the 
starry  heavens  revolve ;  they  also  are  the  proximate  causes  of 
the  succession  of  day  and  night,  and  the  vicissitudes  of  the  sea- 
sons.  The  beauty  and  utility  of  this  arrangement  will  be  ob- 
vious when  we  reflect  upon  these  phenomena.  Although  these 
motions  are  continually  carried  on,  we  are  not  sensibly  conscious 
of  them.  The  case  is  somewhat  similar  to  being  shut  up  in  a 
carriage  which  is  traveling  rapidly  along  a  smooth  road ;  its 
motion  is  not  then  perceptible  ;  or  when  proceeding  in  a  railway 
train,  the  external  scenery  appears  to  be  rushing  past  us  and  we 
seem  quite  at  rest ;  or  it  is  like  the  motion  of  a  ship  in  smooth 
water.  So  it  is  with  respect  to  the  earth's  movements  and  our 
unconsciousness  of  them.  It  may  be  mentioned  here  that  the 
earth  is  no  tardy  traveler,  performing  as  she  does,  according  to 
the  testimony  of  well-accredited  investigators,  her  annual  revo- 
lutions at  the  mean  distance  of  ninety-two  millions  of  miles  from 
the  sun  in  the  short  period  of  twelve  months ;  that  is,  at  the  rate 
of  sixty-eight  thousand  miles  per  hour,  and  rotating  upon  her 
center  in  less  that  twenty-four  hours,  at  the  mean  rate  of  800 
miles  per  hour.  In  her  annual  journeys  she  is  constantly 
escorted  by  a  fair  attendant,  the  Moon,  of  which  we  shall  now 
speak. 

5.  The  Moon.  The  moon  performs  good  service  to  the  earth, 
independently  of  the  supply  of  reflected  light  which  she  trans- 
mits. Her  especial  uses  to  the  earth  will  be  seen  when  we  come 
to  notice  the  tides.  For  the  present  we  shall  present  the  reader 
with  a  view  of  some  of  her  general  features.  Her  diameter  is 
2160  miles  and  she  is  the  subject  of  a  three-fold  motion  :  i.  The 
axillary,  revolving  upon  her  center  in  27  days,  7  hours,  43 
minutes,  n  seconds;  2.  A  local  motion  round  the  earth,  at 
the  distance  of  240,000  miles,  occupying  the  same  period 
as  the  former,  and  constituting  a  lunar  month  ;  and  3.  A  pro- 
gressive motion  with  the  earth  round  the  sun,  performed  in 
13^  lunar  months,  comprising  365  days,  5  hours,  56  minutes, 
57  seconds.  She  resembles  the  earth  in  not  being  a  self-lumi- 
nous, butan  opaque  mass.  The  light  she  exhibits  is  not  inherent, 
as  might  at  first  be  supposed,  but  is  derived  from  the  sun  and 


42  OUTLINES  OF  ASTRONOMY. 

reflected  in  tremulous  rays.  When  viewed  with  a  telescope  her 
disc  displays  a  great  diversity,  one  part  being  covered  with 
bright  spots  and  lines,  and  another  part  overspread  with  dark 
patches  and  shadows.  The  brighter  parts  of  the  moon  are 
mountainous,  as  is  proved  by  the  fact  of  their  casting  shadows 
when  the  sun's  rays  fall  upon  them  obliquely,  and  also  by  the 
ragged  appearance  presented  by  the  interior  illuminated  border 
of  the  moon,  an  appearance  which  can  only  be  satisfactorily 
accounted  for  on  the  supposition  that  the  surface  of  the  moon  is 
not  level,  in  which  case  the  higher  portions  will  be  illuminated 
some  time  before  the  light  reaches  the  level  parts  ;  and  it  is  ob- 
served that  as  the  illumination  proceeds,  bright  spots  start  up  in 
advance  of  it,  and  when  the  moon  is  on  the  wane,  these  same 
spots  continue  to  shine  for  some  time  after  the  surrounding  sur- 
face is  immersed  in  gloom.  The  mountains  occur  either  singly, 
when  they  are  generally  of  a  circular  form,  and  are  called  craters, 
or  in  groups,  which  are  mostly  annular,  and  form  a  sort  of  wall, 
inclosing  a  deep  depression  or  plain,  in  which  are  situated  one 
or  more  conical  mountains.  The  craters  are  not  unfrequently 
eight  or  ten  miles  in  diameter,  and  some  of  the  walled  plains 
measure  more  than  one  hundred  miles  across. 

6.  The  Sun.  The  solar  orb  is  the  great  source  and  center  of 
light  and  heat,  not  only  to  the  globe  which  we  inhabit,  but  also 
to  several  other  bodies  floating  in  the  starry  domains.  In 
appearance,  it  is  of  nearly  the  same  dimensions  as  the  moon, 
but  in  reality  its  diameter  is  414  times  greater.  The  earth 
being  92,000,000  of  miles  from  it,  and  only  240,000  from  the 
moon,  the  former  is  nearly  400  times  more  distant  than  the 
latter;  and  both  objects  appearing  of  the  same  size,  it  follows, 
according  to  the  well  known  law  that  the  apparent  size  of  an 
object  decreases  in  the  ratio  of  its  distance,  that  it  is  also  414 
times  larger.  Its  diameter  is  thus  computed  as  being  850,000 
miles,  which  is  more  than  108  times  that  of  the  earth.  Of  its 
composition  we  cannot  speak  with  any  certainty.  It  is  evidently 
an  immense  volume  of  luminous  matter,  but  as  to  the  specific 
nature  of  this  matter,  there  are  various  opinions,  the  most 
probable  of  which  is,  that  it  consists  of  pure  elementary  fire,  by 
which  is  meant  that  it  is  an  ocean  of  elemental  particles  in  a  state 


O U TLINES  OF  AS TRONOM Y.  43 

of  perpetual  activity.  A  curious  phenomenon  pertaining  to  the 
sun,  is  the  appearance  of  a  number  of  dark  spots  upon  its  sur- 
face, some  of  which  are  not  less  than  forty  thousand  miles  in 
breadth.  From  repeated  observation  of  the  spots,  it  has  been 
conjectured  that  this  vast  orb  experiences  a  rotary  motion  of  25^ 
days  duration.  Spots  were  perceived  on  the  western  margin  ofhis 
disc,  and  were  traced  apparently  across  it,  until  they  disappeared 
on  the  other  side.  From  other  observations  it  was  thought  that 
the  solar  disc  accompanied  the  spots  ;  and  after  making  the 
necessary  deductions  for  the  earth's  change  of  place  during  the 
period  of  a  transit  of  the  spots,  the  time  above  stated  was 
determined  as  the  period  of  an  axial  motion.  The  precise 
nature  of  the  spots  has  led  to  much  speculation  among  astron- 
omers, some  contending  that  they,  are  deep  cavernous  openings 
in  a  luminous  atmosphere  surrounding  the  sun,  and  that  the 
solar  orb  itself  is  an  opaque  mass  discerned  through  the  open- 
ings; while  others  urge,  and  as  we  think  most  reasonably,  that 
they  are  an  incrustation  produced  from  the  solar  matter,  and 
contain  the  materials  of  which  worlds  are  made.  If  the  latter 
theory  be  correct,  they  might  revolve  round  the  sun  without 
carrying  it  along  with  them,  and  hence,  although  the  solar  orb 
doubtless  has  an  axial  motion,  the  above  calculation  of  its 
period  may  be  erroneous.  Be  this  as  it  may,  it  is  quite  certain 
that  the  glorious  orb  which  the  Creator  has  established  to  be  the 
medium  of  communicating  heat  and  light  to  his  multiform 
.works,  is  a  magnificent  and  highly  important  part  of  his  creation. 
Without  his  genial  warmth  and  effulgent  beams,  all  nature  would 
perish.  When  but  partially  withdrawn,  how  languid  and  torpid 
does  she  become  !  assuming  the  shadow  of  death  ;  and  at  his 
reappearance,  how  joyous  and  animated  an  aspect  does  she  wear! 
Deprived  of  its  conservative  influences  of  attraction,  worlds 
would  rush  into  a  wild  chaotic  tumult,  and  eventually  be 
destroyed.  In  all  ages,  the  sun  has  been  an  object  of  peculiar 
regard  ; — venerated  by  the  unlettered,  with  emotions  of  awe 
and  adoration,  and  by  the  learned  as  a  manifestation  of  the 
wisdom  and  goodness  of  nature's  Author.  And  some  deeply- 
searching  philosophic  minds  have  found  delight  in  contemplating 
it  as  a  type  of  the  all-glorious  Being  Himself ;  and  its  pro- 


44  OU TUNES  OF  AS TRONOM F. 

ceeding  heat  and  light  as  emblems  of  the  divine  love  and  wisdom 
which  continually  flow  from  God,  to  vivify,  illuminate,  and  bless 
the  human  race. 

7.  The  Planets.  We  have  now  spoken  of  the  sun,  moon,  and 
earth — a  portion  only  of  our  solar  system.  On  a  starlight  night, 
when  the  glittering  firmament  is  radiant  wiih  loveliness,  and 
eloquent  with  beauty,  amid  that  solemn  stillness  so  congenial 
to  interior  thought  and  pure  aspirations,  the  inquisitive  beholder 
may  discern  a  few  of  the  heavenly  bodies  adorned  in  greater 
splendor,  and  of  somewhat  more  imposing  magnitude,  than 
ordinary  stars.  They  are  known  as  planets,  being  of  an  erratic 
nature,  shifting  their  positions  very  conspicuously,  The  word 
planet,  from  the  Greek,  signifies  a  wanderer.  The  ever-pro- 
gressive movement  of  which  they  are  the  subjects,  distinguishes 
them  from  the  other  heavenly  bodies,  which,  from  their  apparent 
immobility,  are  named  fixed  stars.  Another  feature  by  which  a 
planet  is  distinguished  from  a  fixed  star,  is  that  the  former  is 
never  seen  to  twinkle.  Besides  this,  there  are  a  few  other 
planets  claiming  kindred  with  our  own,  which  are  invisible  to 
the  naked  eye.  These  together  with  their  attendant  moons, 
compose  the  solar  system,  of  which  the  sun  is  the  central  body, 
and  to  each  of  which  he  dispenses  his  invigorating  and  quicken- 
ing beams.  The  planets  already  discovered,  amount  to  56,  and 
have  been  classified  into  two  kinds,  primary  and  secondary. 
The  primary  planets  are  all  those  which,  like  the  earth,  perform  a 
revolution  round  the  sun  ;  and  the  secondary,  those  which  gyrate 
about  their  primaries,  as  the  moon  about  the  earth  The  latter, 
18  in  number,  are  called  satellites,  from  a  word  denoting  an 
attendant.  The  former  are  invariably  known  as  planets  or 
earths.  Of  these,  twenty  are,  at  present,  familiar  to  us.  In 
form,  they  are  very  similar  to  the  earth,  and  likewise  resemble 
it  in  their  motions,  rotating  upon  their  centers,  and  revolving 
round  the  great  luminary.  The  path  described  by  a  planet  in 
its  progressive  journey,  is  termed  its  orbit.  The  orbits  vary 
considerably  in  respect  to  distance  from  the  central  orb,  and 
slightly  in  respect  to  figure.  No  two  travel  at  the  same  dis- 
tance from  the  sun,  nor  in  a  precisely  parallel  plane.  If  it  were 
so,  disturbances  would  ensue.  The  planets  move  in  a  similar 


OUTLINES  OF  ASTRONOMY,  45 

direction,  from  west  to  east,  both  in  their  diurnal  and  annual 
revolutions,  and  by  their  two-fold  motion,  every  portion  of  their 
surface  is  successively,  and  at  stated  intervals,  brought  under 
the  sun's  influence.  This  is  an  infinitely  wise  provision.  Let 
the  contemplative  eye  turn  where  it  may,  it  falls  upon  an 
evidence  of  Infinite  wisdom,  no  less  than  of  Infinite  goodness. 

8.  Astronomers   usually    commence   their   description    of   the 
solar  system  with  the  planet  nearest  to  the  sun,  and  so  proceed 
outwards,    but  some  have  adopted  a  different  course,  and  be- 
ginning  at  the    presumed  boundary  of  the   system    have   pro- 
ceeded towards   the  center,     We  prefer  the  former   method  be- 
cause it  is  most  in  accordance  with  the  order  of   the  discovery, 
and  also  because  it  is  impossible  to  see  that  we   have  yet  ascer- 
tained the  boundaries  of  our  solar  system. 

9.  Mercury,  the  nearest  to  the  Sun,  is  nearly  3,000  miles  in 
diameter.     Its  daily  motion  is  believed  to  be  accomplished  in  24 
hours,  5^  minutes  ;  and  its  annual  revolution  occupies  88  days, 
describing  an  orbit  round   the  central  luminary  at  a  mean  dis- 
tance of   37,000,000  miles.      It  appears   to  the    naked  eye   as  a 
bright  star  ;  but  seen  through  a  telescope,  it  is  found  to  undergo 
increase  and  diminution,  similar  to  the  Moon.     The  cause  of  this 
will  be  apparent  when  an  explanation  is  given  of  the  phases  of 
the  Moon.     Huge  mountains  are  supposed   to  exist  on  the  sur- 
face of  this  planet,  some  of  which  are  much  loftier  than  any  upon 
the  Earth.     Owing  to  its  peculiar  position,  relatively  to  the  Sun 
and  Earth,  from  its  being  within  the  orbit  of  the  latter,  it  is  visi- 
ble only  for  a  short  period  soon  after  sunset  or  before  sunrise. 

10.  Venus,   the  next  in  order,  is   a  beautiful,   lustrous  body, 
often  dazzling  the  eyes  of  the  beholder.     It  is  not  much  inferior 
in   bulk  to  the   Earth,  being  7,800  miles  in  diameter.     Its  orbit, 
68,000,000  miles  from  the  Sun,  is  accomplished  in  225  days,  and 
its  axillary  revolution  in  23  hours,  21  minutes,  19  seconds.     Like 
Mercury,  it  passes  through  various  phases,  sometimes  present- 
ing the  edge  only  of  its  disc  illuminated,  and  at  other  times  its 
full  face.     The  surface  is  variegated  with  mountainous  districts, 
the  principal  of  which  are  in  the  southern  hemisphere.     An  at- 
mosphere has  also  been  detected,  and  some  thought  an  attendant 
moon  was  discernible,  but  this  is  difficult  to  determine,  because 


46  OUTLINES  OF  ASTRONOMY. 

when  between  the  planet  and  our  Earth,  it  would  be  hidden  in 
the  shadow  of  Venus,  and  when  in  any  other  position  its  illu- 
minated side  would  be  beyond  the  sphere  of  observation.  Venus 
is  perceptible  by  the  naked  eye  a  little  longer  than  Mercury,  be- 
fore sunrise  and  after  sunset. 

it.  The  Earth,  that  important  planet  upon  which  it  is  our  lot 
to  be  placed,  is  the  third  in  point  of  distance  from  the  solar  orb. 
Its  diameter  is  7,912  miles,  and  its  circumference  is  about  25,000. 
The  periods  of  its  revolutions  and  its  distance  from  the  Sun 
have  already  been  mentioned  (par.  4).  Its  surface  contains 
about  197,000,000  square  miles.  Of  this,  scarcely  a  third  part  is 
dry  land,  and  not  a  tenth  part  is  inhabited  by  man,  although 
there  are  at  present  upwards  of  r, 000,000.000  human  beings  upon 
it.  It  is  surrounded  by  an  atmosphere  whose  density  is  propor- 
tionate to  its  altitude  ;  the  pressure  at  the  surface  being  equal  to 
15  pounds  per  square  inch.  This  atmosphere  serves  to  temper 
the  solar  rays,  and  to  hold  aqueous  vapors  in  suspension  ;  and 
is  found  necessary  for  the  support  of  animal  life.  An  exposition 
of  its  manifold  uses  and  phenomena  belongs  properly  to  meteor- 
ology and  other  sciences.  We  cannot  speak  with  accuracy  of  the 
matter  composing  the  solid  globe,  since  man  has  never  pene- 
trated much  more  than-  a  mile  below  the  surface.  Some  have 
supposed  it  to  be  quite  hollow,  others  believe  it  to  consist  of  a 
fluid  mass,  either  of  molten  metal,  or  fire  ;  while  some  have 
imagined  it  to  be  filled  with  water.  That  there  is  intense  heat 
beneath  the  surface  is  plain  from  the  existence  of  burning  moun- 
tains, which  belch  out  volumes  of  fire  ;  and  boiling  springs  are 
prevalent  in  some  parts  of  the  world.  The  crust  of  the  earth  is 
found  to  be  composed  of  many  distinct  layers  or  strata  of  earth 
and  mineral  substances,  a  description  of  which  it  is  the  province 
of  geology  to  furnish.  Its  surface  is  adorned  with  a  beautiful  in- 
vestiture of  floral,  arborial  and  cereal  productions  ;  for  an  account 
of  which,  systematically  arranged,  the  sciences  of  botany  and 
arborculture  must  be  consulted.  It  is  also  the  abode  of  some 
thousands  of  distinct  varieties  of  animated  beings,  which  minis- 
ter in  various  ways  to  the  good  of  man,  the  head  of  all  ;  the  sci- 
ence of  natural  history  will  delineate  their  several  characteristics. 
Reflecting  upon  the  peculiarities  of  our  globe,  we  are  impressed 


OUTLINES  OF  A STRONOM Y.  47 

with  the  mutability  of  all  things  mundane.  Scrutinize  whatever 
point  we  may,  there  is  a  continual  process  of  decay,  renovation 
and  systematic  reformation.  Everything  seems  destined,  like 
the  world  itself,  to  perform  appointed  cycles  for  the  production 
of  certain  special  uses.  Man  is  not  exempt  from  these  transfor- 
mations. The  child  advances  into  youth  and  youth  into  man- 
hood; and  the  man,  after  a  few  brief  years,  resigns  his  body  to 
the  tomb,  where  it  undergoes  the  process  of  decomposition,  and 
is  dispersed  into  its  primitive  elements,  and  these  elements  en- 
tering into  the  composition  of  vegetable  and  animal  structures, 
become  again  vitilized  portions  of  other  bodies. 

12.  Mars,  the  planet  next  in  order,  is  a  globe  of  4,500  miles  in 
diameter,   rotating   in   24   hours,    39  minutes,  21^  seconds  ;  and 
performing  its  annual  revolution   at  the  distance  of  144,000,000 
miles  from  the  Sun,  in   the  space  of  686  days,  22  hours,   18  sec- 
onds.    This  planet  is  distinguished  in  the  heavens  by  a  red  and 
fiery  appearance.     A  surrounding  atmosphere  has  been  discov- 
ered, whose  peculiar  composition  may  possibly  occasion  the  red 
appearance.     Lying  beyond  the  boundary  of  the  Earth's  orbit,  it 
does  not  experience  phases,  so  varied,  as  do  Mercury  and  Venus. 
It  is  frequently  seen  gibbous.     Towards  its  northern  and  southern 
extremities,  large  white  patches   are  observable  ;  these  are  con- 
jectured to  be  masses  of  snow  or  ice,  which  remain   unthawed 
during  its  long  winter  season.     It  is  worthy  of  remark,  as  tend- 
ing to  confirm  this  supposition,  that  they  are  not  always  visible, 
but  only  when  the  planet  stands  in  such  a  relation  to  the  Sun  as 
would  induce  winter  at  those  regions.     It  is  also  a  well  known 
law  in  optics  that  anything  white,  but   particularly  snow,  will 
strongly  reflect  the  solar  rays. 

13.  The  Asteroids  or  Small  Planets.     Proceeding  onwards  from 
the  Sun,  we  come  to  a  cluster  of  small  planets,  called,  on  account 
of  their  diminutiveness,   Asteroids.      Thirty-one    have   already 
been  discovered.     They  describe  orbits  at  no  great  distance  from 
each  other,  but  very  irregular;  they  all  experience  a  rotary  motion. 
Their  periods  of  revolution  vary  from  3  to  5  years.     One  only  is 
visible  to  the  naked  eye.     Some  astronomers  have  conjectured  that 
these   are   fragments  of  a  disruptured  planet,  which  originally 
traversed  that  portion   of  the   heavens.     They  are  named  Ceres, 


48  0  U TUNES  OF  A  S TRONOM  Y. 

Pallas,  Juno,  Vesta,  Astrsea,  Hebe,  Iris,  Flora,  Hygeia,  Diana, 
Parthenope,  Oceanica,  Victoria,  etc.  The  first  four  were  discov- 
ered from  1801  to  1807;  and  the  others  have  been  discovered  since 
1845.  More  will,  doubtless,  yet  be  added  to  the  list. 

14.  Jupiter.     This,  the  largest  of  all  the  planets,  whirls  in  its 
appointed  orbit  at  the  distance  of  496  million  miles  from  the  Sun, 
in  the  space  of  n  years,  3 1 5  days,  8  hours,  58  minutes,  27  seconds; 
traveling  at  the  almost  incredible  rate  of  29,840  miles  every  hour. 
This  immense  mass,   90,000  miles  in   diameter,  (which  is  eleven 
times  that  of  the  Earth),  rotates  in  the  space  of  9  hours,  55  minutes, 
33  seconds;  at  the  average  speed  of  28,000  miles  per  hour.    A  pecul- 
iarity connected  with  this  planet,  which  has  not  yet  received  a  satis- 
factory solution,  is  the  appearanceof  a  numberof  darkstreaks  sur- 
rounding it,  in  the  form  of  belts,  which  are  found  to  vary  consid- 
erably ;  sometimes  appearing  to  be  ruptured,  and  then  vanishing 
entirely.     Large  spots  have  been  observed  in  these  zones;  and 
when  the   belts  have  disappeared  the  spots  have  vanished  also. 
From   this,  some  astronomers  have  inferred  that  they  are  clouds 
floating  in  the  atmosphere  of  the  planet.     The  belts  are  supposed 
to  be  certain  tracts  of  comparatively  clear  sky  subsisting  in  the 
atmosphere,   induced  by   peculiar  atmospheric  currents,    some- 
thing like  our  trade  winds,  but  not  so  variable,  and,  according  to 
this  theory,  the  spots  are  presumed  to  be  the  dark  body  of  the 
planet  seen  through  openings  in  the  belts.     Jupiter  is  favored 
with  the  attendance  of  4  satellites,  which  are  continually  revol- 
ving round    him,  and  accompany    him    in   his  annual  progress 
about  the  Sun.     His  nearest  moon  revolves  in  an  orbit  of  259,000 
miles  from  his  center  ;  the  second  at  482,000,  the  third  at  683,000 
and  the  fourth  at  the  distance  of  1,202,000  miles.     The  periods  of 
their  revolutions  vary  from  i  day,  i8j^  hours,   to  16  days,   16^ 
hours.    Theirorbital  arraqgement  is  such  that  theprimary  is  never 
destitute  of  twilight.      The  smallest  of  these  silent  wanderers  is 
larger  than  our  moon,  and  each  is  subject  to  occasional  eclipses. 
Jupiter  is  inferior  to  none  but  Venus  in  brilliancy  ;  and,  in  bulk. 
exceeds  the  Earth  1,300  times. 

15.  Saturn.     This  planet  describes  the  next  outermost  circle 
round  the  Sun.     It  is  a  globe  of  about  78,000  miles  in  breadth  ; 
has  a  diurnal  motion,  occupying  10  hours,  16  minutes,   19  sec- 


O  U  T LINES  OF  A  S  TRONOM  Y.  49 

onds;  and  a  periodical  revolution  at  the  mean  distance  of 
900,000,000  miles  in  10,747  days,  that  is,  nearly  30  years.  This 
planet  is  less  bright  than  all  the  other  primaries,  except  Uranus 
and  Neptune  ;  and,  like  Jupiter,  is  surrounded  by  a  kind  of  zones, 
which,  from  the  great  fluctuations  they  undergo,  appear  to  be  a 
species  of  subtle  matter  floating  round  the  body  of  the  primary. 
A  peculiar  feature  in  reference  to  this  globe  is  the  existence  of 
several  concentric  rings  encompassing  it.  They  consist  of 
opaque  matter,  and  are  supposed  to  receive  light  from  the  solar 
orb,  and  reflect  it  upon  the  body  of  the  planet.  That  the  rings 
are  constituted  of  some  dense  substance  is  evident  from  their  re- 
flected shadow  upon  that  side  of  the  planet  nearest  the  Sun  and 
the  shadow  of  the  planet  on  the  opposite  interior  side  of  the 
rings.  The  largest  ring  is  about  200,000  miles  in  breadth. 
Saturn  has  S  moons,  one  of  which  is  of  very  recent  discovery. 
These  accompany  the  planet  with  so  nicely  adjusted  regularity 
that  every  portion  of  its  surface  is  kept  enlightened  by  one  or 
the  other  of  them.  They  are  of  variable  sizes  and  distances,  the 
nearest  being  11,400  miles,  while  the  most  remote  is  no  less  than 
2,272,000  miles  distant  from  the  planet.  The  periods  of  their 
revolutions  are  proportionately  diverse,  ranging  from  i  day  to  79 
days,  8  hours. 

16.  Uranus.  Advancing  in  our  outward  travel,  to  a  distance  of 
900,000,000  miles  from  Saturn,  we  come  upon  a  member  of  the 
solar  system  which,  till  the  year  1845,  was  considered  the  re- 
motest planet.  Its  diameter  is  35,112  miles.  It  is,  therefore,  in- 
ferior to  both  Saturn  and  Jupiter,  but  is  about  eighty  times  the 
size  of  the  Earth,  Its  axial  motion  has  not  been  ascertained  ; 
its  periodical  revolution,  at  1,800  million  miles  from  the  Sun,  oc- 
cupies 84  years.  One  of  its  years,  therefore,  would  be  equal  in 
duration  to  an  ordinary  lifetime  on  our  planet.  It  moves  in  its 
orbit  at  the  rate  of  15,000  miles  per  hour.  On  account  of  its  great 
distance  it  cannot  be  distinguished  from  a  fixed  star  without  the 
aid  of  a  magnifying  power  of  200  times.  Four  satellites  have 
been  discovered  and  two  more  are  supposed  to  exist.  Uranus 
was  discovered  by  Sir  William  Herschel,  father  of  Sir  John  Her- 
schel,  in  1781.  and  was  for  some  time  known  as  the  planet  Her- 
schel. It  was  also  called  the  Georgium  Sidus,  in  honor  of  the 


5o  OUTLINES  OF  ASTRONOMY. 

reigning  monarch,  George  III.;  but  the  name  Uranus  is  now 
universally  recognized.  In  the  ancient  mythology  Uranus  was 
the  father  of  Saturn,  as  Saturn  was  of  Jupiter,  and  Jupiter  of 
Mars. 

17.  Neptune.     This  is  the  name  given  to  a  recently  discovered 
planet  which  traces  its  path  among  the  solitary  fields  of  ether  at 
the  almost  inconceivable  distance  of  3,000,000,000  miles  from  its 
solar  center.     It  accomplishes  its  journey  in  about   164  years. 
Its  diameter  is  computed  at  about  31,000  miles.     The  period  of 
its  diurnal  motion   has  not  been  precisely  determined.     One  at- 
tendant moon  has  lately  been  discovered,  and  it  is  supposed  that 
there   are    others.      Something  bearing   the   appearance   of   an 
engirding  ring,  similar  to  the  rings  of  Saturn,  has  been  partially 
observed. 

18.  The  discovery  of  this  planet,  so  far  removed  from   us  in 
the  regions  of  space,  has  perhaps  done  more  to  verify  the  mathe- 
matical  accuracy   of  astronomical  calculations   than   anything 
hitherto  achieved.     Long  previous  to  its  actual  observation,   its 
existence  was  surmised.     Several  astronomers  had  noticed   the 
perturbations,    experienced   by  Uranus  in   its  orbital  progress. 
At  one  period  this  planet  was  found   more  regular  than  at  an- 
other.    Supposing  no  disturbing  cause  existed,  his  precise  posi- 
tion in  any  part  of  the  heavens,   at  any  given   time,   could  have 
been    predicted    with   certainty.     Actual   observation   was    not 
found  to  coincide  with  the  prediction.     From   1795  to   1822,   his 
actual  place  was  in  advance  of  his  computed  place  ;  from  1822  to 
1830  he  was  observed  to  retrograde,   until,   at  length,  the  com- 
puted and  observed  positions  agreed,    and  it  went  on   gradually 
receding.     Knowing  there  must  be  some  cause  for  these  disturb- 
ances, and,  recognizing  that  law  in    dynamics,   that   masses   of 
matter  exert  a  reciprocal  attractive  force  upon  each  other  accord- 
ing to  their  bulk  and  distance,  and  finding  that  the  influences 
interior  to  the  orbit  were  not  adequate  to  produce  the  perturba- 
tions witnessed,  astronomers  concluded  there  must  be  some  huge 
body  revolvinginanoutercircle, beyond  the  boundaries  of  Uranus. 
Some  astronomers  consequently   betook  themselves  to  the  task 
of  discovering,  if  possible,   the  position  of  the  supposed  extra- 
neous body,  and  two  gentlemen  in   particular  arrived  at  very 


OUTLINES  OF  ASTRONOMY.  51 

nearly  the  same  results,  namely,  Mr.  Adams,  an  undergraduate 
of  the  University  of  Cambridge,  and  Monsieur  Leverrier,  a 
French  astronomer.  The  latter,  however,  made  the  nearest  ap- 
proximation to  the  truth,  as  to  the  position  of  the  disturbing 
body,  and  proceeded  further  to  describe  its  magnitude,  the  figure 
of  its  orbit,  etc.  He  is  considered,  therefore,  as  justly  entitled 
to  the  honor  of  the  discovery.  But  all  this  was  as  yet  only  hypo- 
thetical ;  the  planet  still  remained  to  be  seen.  Leverrier  had 
expressed  himself  upon  the  subject  as  follows  : — ''  Theory  and 
observation  appear  to  contradict  each  other  when  Uranus  is 
concerned — the  planet  which  gravitates  on  the  confines  of  cur 
system.  Well  !  neither  one  nor  the  other  is  wrong  !  In  order 
to  re-establish  this  agreement,  broken  in  appearance,  it  only  re- 
quires to  admit  the  existence  of  a  star  of  the  same  nature,  but 
more  distant,  disturbing  by  its  influence  the  regular  movements 
of  Uranus.  This  Star  no  one  has  seen,  but  it  exists.  I  have  meas- 
ured its  distance,  weighed  its  bulk,  and  estimated  its  diameter 
//  is  there,  seek,  and  you  will  discover  it!  "Certainly,"  says  Mon 
sieur  Arago,  in  a  paper  read  before  the  Academy  of  Sciences  at 
Paris,  "never  did  a  more  bold  assertion  receive  a  more  striking 
confirmation.  Monsieur  Leverrier  writes  to  Monsieur  Galle,  at 

4 

Berlin.  The  letter  reaches  him  in  the  morning.  The  same  night 
he  points  his  telescope  to  the  exact  point  of  the  heavens  indi- 
cated by  the  French  astronomer,  and  immediately,  without  any 
searching  being  required,  he  finds  the  predicted  planet,  which 
for  so  many  centuries  had  remained  hidden  from  us."  This  case 
affords  an  instance  of  the  certainty  of  mathematical  deductions. 
An  object  is  physically  observed  from  data  furnished  by  one 
who,  although  he  had  not  seen  it,  had  intellectually  discovered  it. 
19.  It  has  been  calculated  that  the  mass  of  all  the  planets  to- 
gether would  not  exceed  a  6ooth  part  of  the  Sun's  bulk  ;  and  the 
area  embraced  within  the  orbit  of  the  remotest  planet  yet  dis- 
covered, comprises  a  region  of  space  equal  to  six  thousand 
million  miles  in  breadth,  and  nearly  nineteen  thousand  million 
in  circumference.  And  this  expansive  system,  comprehending 
within  its  limits  so  vast  a  region  as  to  be  scarcely  appreciable  to 
human  intellect,  what  is  it  in  comparison  with  the  wide  domains 
spreading  all  around  and  beyond  in  every  direction  ?  what  in- 


52  O U TUNES  OF  AS TROXOM Y. 

deed  but  a  mere  speck  in  the  great  universe,  a  small  item  of  the 
furniture  of  the  heavens?  Well  might  one  of  old  exclaim,  under 
a  sense  of  its  magnificence,  "the  heavens  declare  the  glory  of 
God,  and  the  firmament  showeth  his  handiwork."  The  compara- 
tive size  and  circuit  of  the  planets,  has  been  illustrated  by  Sir 
John  Herschel,  as  follows  : — "  Select  a  well-leveled  field  or  bowl- 
ing green.  In  the  center,  place  a  globe  two  feet  in  diameter,  to 
represent  the  Sun  ;  a  grain  of  mustard  seed  will  denote  Mercury, 
placed  on  the  circumference  of  a  circle  164  feet  in  diameter,  to 
represent  its  orbit  ;  and  Venus  will  be  denoted  by  a  pea,  placed 
on  a  circle  284  feet  in  diameter.  The  earth  will  be  also 
a  pea,  on  a  circle  430  feet  ;  and  a  rather  large  pin's 
head,  on  a  circle  of  654  feet,  shows  Mars;  grains  of  sand, 
on  circles  or  orbits  of  from  1000  to  1200  feet,  repre- 
senting Juno,  Ceres,  Vesta,  Pallas,  Astrea,  and  the 
other  small  planets  recently  discovered.  Jupiter  will  re- 
quire a  middling-sized  orange  for  his  representative,  in  a 
circle  nearly  half  a  mile  across  ;  Saturn  a  small  orange  on  a 
circle  four-fifths  of  a  mile  ;  and  Uranus  a  full-sized  cherry,  or  a 
small  plum,  upon  a  circle  of  more  than  a  mile  and  a  half  in 
diameter."  An  ordinary  plum v on  a  circle  of  two  miles  and  a 
half,  would  represent  Neptune. 

20.  A  brief  description  of  the  planetary  bodies  composing  our 
solar  system,  has  now  been  given,  from  which  it  will  be  seen  that 
in  magnitude,  the  Earth  is  superior  to  15,  and  inferior  to  4  of 
the  primary  planets.  What  legitimate  inference  may  we  draw 
from  this  fact?  Do  these  capacious  globes  exist  simply  for  the 
good  of  mankind  upon  this  Earth  ?  They  resemble  it  in  form, 
are  governed  by  the  same  physical  laws,  are  subject  to  the  same 
mutations  ;  and  are  we  not  compelled  to  conclude  that  they  exist 
for  the  same  purposes  ?  As  far  as  their  light  is  concerned,  they 
are  of  comparatively  little  service  to  us,  nor  have  they  any 
perceptible  influence  in  maintaining  the  established  order  of 
things  upon  our  planet  ;  some  of  them,  too,  are  not  discernable 
without  the  aid  of  magnifying  glasses.  What  use,  then,  in  the 
vast  economy  of  nature,  can  they  subserve  ?  That  they  have 
important  uses  to  fulfill,  it  would  be  impious  to  deny,  for  ihe 
Creator  has  made  nothing  in  vain.  Have  they  been  framed  to 


OUTLINES  OF  ASTRONOMY.  53 

display  His  omnipotence,  and  hence  to  exalt  our  conceptions  of 
His  glorious  perfections?  If  so,  our  conceptions  are  only  really 
elevated  in  proportion  to  our  perception  of  their  uses.  Is  not 
every  reflecting  mind  conscious  that  everything  is  valued  accord- 
ing to  its  estimated  usefulness  ?  Viewing  them  as  capacious 
seminaries  expressly  designed  to  people  the  spiritual  universe 
with  happy  subjects,  do  we  not  assign  to  them  the  highest  of  all 
uses,  and,  regarding  them  in  this  light,  are  we  not  animated  with 
emotions  of  the  profoundest  reverence  towards  that  Divine 
Being,  who  is  manifestly  so  great,  not  only  in  power,  but 
in  goodness — which  constitutes  true  greatness  ?  This  view  is 
quite  compatible  with  analogical  reasoning ;  for,  if  this  be 
the  end  of  creation  upon  our  Earth,  those  far  distant  spheres 
so  much  resemble  ours  in  their  physical  properties,  and  in 
all  that  we  know  of  them,  that  it  must  be  predicable  of  them 
also. 

21.  Comets.  These  form  a  numerous  class  of  celestial  bodies, 
whose  true  nature  and  uses  are  at  present  involved  in  obscurity. 
A  Comet  is  a  fiery  meteor,  scientifically  divided  into  four  general 
parts  :  the  nucleus,  which  is  the  most  dense  portion,  being  opaque ; 
the  head,  that  is,  the  light  part  surrounding  the  nucleus;  the 
coma,  a  lighter  portion  than  the  preceding,  which  forms  a  halo 
around  the  head  ;  and  a  tail,  composed  mostly  of  a  long  stream 
of  light  projected  beyond  the  body  of  the  comet.  The  matter  of 
the  tail  is  very  much  attenuated,  and  is  quite  transparent. 
Whether  these  fiery  wanderers  are  really  members  of  our  system, 
is  problematical.  Three  only  have  been  ascertained  to  observe 
anything  like  a  definite  period  and  course  of  revolution  round 
the  Sun.  Of  these,  the  principal  one  is  known  is  Halley's 
comet,  whose  revolution  occupies  75  years.  Its  last  appearance 
was  in  1835,  at  the  time  which  had  been  computed  for  it.  An- 
other has  been  found  to  revolve  in  about  3^  years  ;  and  it  is 
worthy  of  remark,  that,  upon  each  return  of  this  body,  its 
period  of  revolution  is  found  to  lessen.  Its  orbit  is,  therefore, 
gradually  becoming  more  circumscribed,  or  its  velocity  is 
increasing.  A  third  comet  has  been  observed  to  fulfill  its  revo- 
lution in  6%  years,  and  it  is  rather  remarkable  that  this  has  no 
tail.  Another,  which  appeared  in  1680,  is  assumed  to  have  a 


54  0 U TUNES  OF  AS TRONOM  Y. 

period  of  575  years.  The  few  whose  periods  have  been  deter- 
mined with  some  degree  of  certainty,  form  but  a  very  small 
number  in  comparison  with  those  which  sometimes  appear  within 
the  confines  of  our  system,  and  then  are  lost  to  view;  some 
never  more  to  reappear,  and  others  at  exceedingly  long  intervals 
and  indefinite  periods.  One  known  as  Leslie's  comet  was  twisted 
by  the  action  of  Jupiter  out  of  its  proper  orbit  into  a  short 
ellipse,  and,  after  passing  twice  round  the  Sun  in  such  ellipse, 
was,  by  the  same  planet,  twisted  back  again,  and  driven  off 
into  the  depths  of  space,  probably  to  revisit  us  no  more.  The 
orbits  of  all  the  comets  are  very  irregular,  approaching  near  the 
Sun,  and  then  retiring  to  a  great  distance.  About  150  of  these 
heavenly  visitants  have  been  made  the  subjects  of  scientific 
investigation,  but  their  true  constitutions  and  capabilities  still 
elude  the  keenest  observation.  When  noticing  their  changes, 
the  question  naturally  occurs, — What  are  they  ?  Can  they  be 
earths  in  a  state  of  formation,  composed  of  light  ethereal 
particles,  a  kind  of  fire-mist,  which,  gradually  condensing, 
merges  into  vapory  and  earthly  matters.  Some  have  imagined 
them  to  be  suns,  in  an  incipient  state  of  progressive  formation. 
We  must,  however,  leave  them  at  present  veiled  in  obscurity, 
believing  that,  as  science  advances,  and  the  intellect  of  man 
becomes  free  to  perceive  and  judge  accurately,  and  his  affections 
become  hallowed  and  attuned  to  the  right  use  of  knowledge,  all 
uncertainty  will  be  dispersed  from  this  as  from  other  subjects, 
and  the  glowing  brilliancy  of  truth  will  illuminate  the  whole  of 
the  works  of  God. 

22.  Having  now  traveled  over  so  vast  an  area  of  nature's 
empire,  it  becomes  us  to  retrace  our  steps,  and  note  down  a  few 
of  the  most  important  phenomena  associated  with  our  terrestrial 
dwelling-place.  In  doing  so,  we  shall  find  occasion  to  admire 
the  advantages  resulting  from  the  beautiful  construction  of  our 
little  universe  ;  for,  it  is  little  compared  with  the  boundless  realms 
of  the  great  Creator's  works.  In  the  smallest  things  of  nature,  we 
can  see  an  epitome  of  the  greatest;  we  shall  find  her  amenable 
to  laws  impressed  upon  her  at  her  birth,  from  which  she  cannot 
deviate ;  they  govern  in  the  formation  of  an  atom,  as  in  the  con- 
struction of  a  world.  The  same  law  which  presides  over  the 


0 U TUNES  OF  AS TRONOM  Y.  5 > 

globular  form  of  the  dew-drop,  imparts  rotundity  to  the  globe 
itself. 

23.  Day  and  Night.     These  phenomena  result  from  the  Earth's 
rotatory  motion.     As  already  observed,  she  is  perpetually  whirl- 
ing round   upon  her  center.     To  illustrate  this,   imagine  a  rod 
passed   perpendicularly  through  the   middle   of    the   Earth,  pro- 
jecting at  the  two  extremities,  upon  which  she  turns,  as  a  bobbin 
on  a  spindle.     This  imaginary  rod  is  termed  its  axis,  and  the 
upper  projecting  point  is  the  north,  and  the  under  the  south,  pole. 
Now  it  must  be  obvious  that  as  the  Sun  is  relatively  a  stationary 
body,  and  the  Earth   is  constantly  revolving  upon  its  presumed 
axis,  that  portion  of  her  surface  which  is  now  presented  towards 
the  luminary,  will,  erelong,  be  turned  away  from  him.     While 
presented  to  him,  the  solar  light  is  received,  and  day  is  the  con- 
sequence; when  averted,  there  is  a  deprivation   of    light,   and 
night  ensues.  < 

24.  The  Inequality  of  Day  and  Night.      The  thoughtful  learner 
will  perhaps  ask.  If  the  foregoing  be  correct,  why  are  the  days 
and  nights  so  unequal  in  duration  ?    We   proceed  to  answer  this 
inquiry.     It  must  be  remembered  that  the  Earth  is  the  subject  of 
two  kinds   of   motion,  (par.  4)  that  during  every  moment  she  is 
spinning  round  upon  her  axis,  she  is  at  the  same  time  progress- 
ing in  a  circle    through   the  realms  of  space.     A  familiar  illus- 
tration of  these  distinct   movements  is  furnished  by   rolling  a 
ball  upon  the  ground,  which,  while  it  advances,  is  also  revolving 
upon   its   center.     The   alternate  diurnal   changes,  as  we   have 
seen,  are  the  product  of    the     axial     movement,     but  the  variable 
length  of  each  depends  upon  the   progressive  or  orbital  motion. 
In  her  annual  journey,  the  Earth  continually  shifts  her  position 
with  respect  to  the  Sun.    But  these  local  changes  are  not  sufficient 
to  account  for  the   irregularity  of  day  and   night,  for  supposing 
the    Earth's   rotation   to   be   performed   always    with  the   same 
velocity  ;  what  difference  could  be  made  relative  to  light  and 
darkness  by  her  position  in  one  part  of  her  orbit  more  than  at 
another?     Why,  then,  are  not  the  day  and  night  always  equal, 
since  we  find  that  they  are  so  at  certain   seasons  of  the   year. 
This,  indeed,  would  be  the  case  if  our  globe  traversed  its  annual 
path  in  a  perpendicular  position,  that  is,  with  the  north  pole  ever 


56  OUTLINES  OF  ASTRONOMY. 

pointing  upright  from  its  orbit.  But  this  is  not  the  case.  The 
Earth  journeys  onward  with  her  axis  always,  in  reference  to  her 
orbit,  in  a  slanting  direction,  and  maintains  this  situation 
throughout  her  annual  revolution  ;  her  north  pole  being  pre- 
sented towards  a  particular  point  in  the  northern  heavens.  By 
this  arrangement  it  is  evident  that  during  the  progress  of  its 
circuit,  no  spot  upon  its  surface  can  stand  exactly  in  the  same 
relation  to  the  Sun  for  any  length  of  time.  At  two  periods  of 
her  course,  (as  will  be  shown  when  speaking  of  the  seasons)  she 
is  so  situated  as  to  receive  the  solar  beams  directly  upon  her 
central  portions,  and  this  produces  a  day  and  night  of  equal 
duration  all  over  the  world;  while  at  another  period,  her  position 
is  such  that  the  regions  about  the  north  pole  enjov  perpetual 
light  for  some  months,  and  at  another  period  the  south  pole  is 
similarly  illuminated. 

25.  7^i?  Figures  of  the  Earth's  Orbit  Explanatory  of  the  Varia- 
tions of  Day  and  Night.  It  has  been  found  by  patient  observation 
that  in  performing  her  periodical  revolution  round  the  Sun.  the 
Earth  does  not  proceed  in  a  horizontal  plane;  that  is,  she  does 
not  progress  in  direct  line  round  the  center  of  the  Sun,  but  de- 
scribes a  slanting  circle.  At  one  portion  of  her  orbit,  she  is  a 
little  below  the  horizontal  line,  or  the  Sun's  equator  ;  and  at  the 
opposite  point  she  is  a  little  above  it.  Her  .situation  at  these 
two  stages  of  her  progress  respectively  constitute  her  longest  and 
shortest  day.  It  is  clear  that  while  located  at  the  lowest  point, 
the  northern  portion  of  the  globe  is  more  immediately  receptive 
of  the  solar  rays,  while  the  southern  portion  will  remain  in  com- 
parative obscurity,  and  the  extreme  south  will  be  involved  in 
total  darkness.  This  point  is  attained  on  the  2ist  of  June,  when 
the  day,  in  Great  Britain,  is  more  than  16^  hours  long.  The 
north  pole  now  enjoys  an  uninterrupted  day  of  some  months' 
duration.  Rising  steadily  from  this  her  lowest  position  in  the 
direction  indicated,  the  Earth  in  due  time  comes  to  that  portion 
of  her  orbit  where  the  horizontal  and  oblique  lines  intersect  each 
other,  and  here  a  complete  half  of  her  surface  is  presented  to 
the  Sun  ;  hence  results  an  equal  day  and  night  throughout  the 
globe,  the  Sun  rising  at  six  and  setting  at  six.  Proceeding  on- 
ward, daylight  in  the  north  gradually  decreases,  because  the 


OUTLINES  OF  ASTRONOMY.  57 

northern  hemisphere  is  more  and  more  averted  from  the  solar 
beams,  until  arriving  at  the  highest  point,  the  boundary  of  her 
oblique  wanderings,  which  happens  on  the  2ist  of  December, 
the  shortest  day  is  experienced  by  those  parts  north  of  the 
equator,  and  the  extreme  south  is  illuminated  with  unceasing 
light.  Having  attained  this  altitude  (which  is  her  highest  position 
to  the  inhabitants  of  the  south),  she  commences  her  descent,  and 
step  by  step,  goes  down  the  inclined  plane  on  the  opposite  side 
of  the  Sun,  till  again  reaching  the  point  where  she  crosses  the 
horizontal  line,  which  is  the  Sun's  equator,  her  surface  is  illumi- 
nated from  pole  to  pole,  and  an  equal  day  and  night  of  twelve 
hours  is  again  realized.  Proceeding  downwards  in  her  travel, 
she  finally  arrives  at  the  point  whence  we  started  ;  her  northern 
hemisphere  is  then  lighted  up,  variegated  beauty  adorns  its 
surface,  and  it  once  more  rejoices  in  a  plenary  reception  of  the 
solar  rays,  while  the  south  pole  is  again  passing  through  a  long 
and  wintry  night.  How  beautifully  does  all  this  shadow  forth 
the  changes  of  human  life  !  How  eloquent  is  nature,  to  the 
soul  attuned  to  its  divine  harmonies  !  What  lessons  of  fertile 
wisdom  may  be  gleaned  from  the  movements  and  positions  of 
the  terrestrial  globe  ! 

26.  Phases  or  Changes  of  the  Moon.  The  Moon  revolving  upon 
her  axis  presents  every  portion  of  her  surface  towards  the  Sun  at 
stated  intervals,  and  thus  receives  his  light,  a  portion  of  which  is 
reflected  or  thrown  back  from  her  illuminated  disc;  the  portion 
so  reflected  is  moon-light.  But  we  find  that  the  intensity  of  moon- 
light varies  considerably,  and  at  times  is  entirely  absent,  on 
account  of  the  moon  being  partially  or  wholly  invisible.  The 
aspects  presented  by  the  Moon  during  her  several  changes,  are 
called  phases,  from  a  Greek  word  signifying  appearances.  When 
she  is  in  that  part  of  her  orbit  which  lies  between  the  Sun  and 
the  Earth,  her  illuminated  side  is  hidden  from  view.  She  is  then 
invisible,  and  we  have  no  moon-light,  and  the  Moon  is  said  to 
change.  As  she  proceeds  in  her  circuit,  a  portion  of  her  luminous 
surface  appears  in  the  form  of  a  bright  edge.  We  then  have 
new-moon.  This  bright  edge  gradually  widens,  as  the  Moon 
advances,  till  half  her  disk  is  exhibited  ;  when  we  have  what  is 
called  half-moon.  She  travels  on  and  on,  until,  arriving  at  the 


58  .        OUTLINES  OF  ASTRONOMY. 

side  of  the  Earth  most  distant  from  the  Sun,  the  whole  of  her 
illuminated  surface  is  visible,  and  there  is  full-moon.  She  then 
goes  through  a  similar  process  of  diminution.  That  the  Moon, 
like  the  Earth,  is  an  opaque,  and  not  a  self-luminous,  body,  is 
evident  from  the  nature  of  eclipses,  upon  which  we  shall  now 
offer  a  few  remarks. 

27.  Eclipses.  An  eclipse  is  a  total  or  partial  deprivation  or 
obscuration  of  light,  either  from  the  Sun  or  Moon.  In  some 
total  eclipses  of  the  Sun.  the  darkness  has  been  so  great  as  to 
exhibit  the  stars  at  noon-day.  An  eclipse  of  the  Sun  occurs 
when  the  Moon  gets  between  it  and  Earth.  An  eclipse  of  the 
Moon  happens  when  the  Earth  comes  in  a  direct  line  between  it 
and  the  Sun.  A  solar  eclipse  can  never  occur  but  at  the  time  of 
the  Moon's  change,  nor  can  one  of  the  Moon  take  place  at  any 
other  time  than  when  she  is  full.  Both  solar  and  lunar  eclipses 
can  be  predicted  with  perfect  accuracy.  To  understand  the 
causes  of  an  eclipse  it  is  necessary  to  refer  to  par.  25  ;  for  the 
Moon  does  not  travel  round  the  Earth  in  a  horizontal  plane.  If 
it  were  so,  there  would,  of  necessity,  be  two  eclipses  every  month, 
one  lunar  and  one  solar  ;  whereas  it  is  well  known  that  although 
there  must  be  two  of  the  Sun  annually,  yet  there  may  be  no 
eclipse  of  the  Moon  in  the  same  year.  The  phenomenon  is  only 
explicable  by  the  real  motion  of  the  Moon  about  the  Earth  being 
the  same  as  that  of  the  Earth  round  the  Sun,  namely,  in  a  slant- 
ing direction.  This  oblique  line,  is  called  the  ecliptic,  because  it 
is  only  when  a  body  is  interposed  in  some  portion  of  this  track 
that  an  eclipse  can  take  place,  and  then  it  can  only  happen  when 
the  intervening  body  is  at  that  point  where  the  orbits  of  the 
Earth  and  Moon  intersect  each  other  in  a  right  line  with  the  Sun. 
Now  if  the  Moon  were  in  such  a  position  that  a  right  line  drawn 
through  its  center  would  strike  the  center  of  the  Sun,  then  the 
Sun  would  be  hidden,  except  a  portion  which  would  be  seen  en- 
circling the  Moon.  This  is  called  an  annular  eclipse.  Suppose 
the  Moon  to  be  on  the  opposite  side  of  the  Earth,  the  latter, 
being  so  much  larger  than  the  Moon,  would  intercept  so  many 
of  the  Sun's  rays  as  to  obscure  its  entire  disc,  and  hence  results 
a  total  lunar  eclipse.  The  number  of  eclipses  vary  from  two 
to  seven  in  the  year,  and  it  is  found  that  the  Moon  has  to  perform 


0 U TLINES  OF  AS TROXOM Y.  59 

233  monthly  revolutions,  before  she  enters  into  the  same 
position  with  the  Sun  and  Earth,  in  which  she  is  at  any  given 
time.  These  occupy  about  nineteen  years;  so  that  there  is 
a  regular  cycle  of  the  movements  of  Sun,  and  Moon,  and  Earth 
of  about  nineteen  years'  duration. 

28.  Eclipses  of  the  Satellites.  The  attendant  moons  of  other 
planets  are  ascertained  to  be  subject  to  eclipses  similar  to  our 
own.  Jupiter's  moons  have  been  observed  to  experience  them 
very  frequently,  and  they  can  be  predicted  with  certainty.  They 
present  a  rather  curious  appearance,  the  eclipsed  satellite  seem- 
ing to  be  suddenly  obliterated  from  the  firmament  and  as  sud- 
denly re-appearing.  The  eclipse  of  other  satellites  has  been 
observed. 

20,.  Tides.  These,  whatever  may  be  their  cause,  form  an  im- 
portant feature  in  the  Creator's  works,  and  manifest  great  design 
and  adaptation  in  their  arrangement.  We  all  know  how  soon 
stagnant  water  becomes  corrupt,  and  unfit  for  the  purposes  of 
life.  If  the  waters  encircling  the  Earth  were  to  remain  sta- 
tionary for  any  length  of  time,  a  decomposing  process  would  go 
on,  engendering  noxious  and  miasmatic  vapors  and  thus  loading 
the  atmosphere  with  subtle  poison.  To  obviate  this,  is  one  of 
the  uses  of  the  tides.  By  the  continual  ebbing  and  flowing  of 
the  waters  of  the  ocean  the  salubrious  element  is  preserved  in  a 
purer  condition,  adapted  to  man's  necessity. 

30.  There  are  two  general  daily  ebbings  and  flowings  of  the 
waters,   the   interval   between   each  rising   being   12   hours,  25 
minutes,  so  that  two  complete  tides  go  through  their  course  in 
about  24  hours,  50  minutes.     Hence,  as  a  day  comprises  only 
24  hours,  the  time  of  high  water  is  about  50  minutes  later  at  any 
particular  place  on  each   succeeding  day.     The  tides  are  found 
to  differ  considerably  in  elevation,  the  mean  high-water  mark 
being  five  feet  above   the  level,  but  sometimes  rising  to  seven, 
and  at  other  times  depressed   to  three  feet  only.     Astronomers 
have  attributed  the  tides  to  solar  and  lunar  influences,  but  more 
especially  to  the  influence  of  the  Moon.     The  theory  generally 
accepted  is  as  follows  : 

31.  Cause  of  the  Tides.     In  agreement  with  that  law  by  virtue 
of  which  falling  bodies  are  precipitated  to  the  Earth,  and  which 


60  OUTLINES  OF  ASTRONOMY. 

is -called  the  attraction  of  gravitation,  it  is  argued  that  large 
masses  of  matter  floating  in  space  are  mutually  attracted 
towards  each  other,  and  that  thus  the  Sun  and  Moon  exert  an 
attractive  force  upon  the  Earth  ;  but  the  water  being  a  fluid 
mass,  and  consequently  more  mobile,  presents  less  resistance  to 
the  disturbing  action,  and  is  therefore  drawn  out  of  its  place  to  a 
greater  extent  than  the  solid  matter,  by  the  attractive  influence 
of  the  Moon.  [And  thus  are  caused  the  tides  :  the  Spring-tide 
when  the  Sun  and  Moon  are  on  the  same  side  or  opposite  sides  of 
the  Earth  ;  Neap-tide,  when  the  Sun  is  quarter  way  round  from  the 
Moon.]  A  peculiarity  worthy  of  remark  is,  that  the  water  does 
not  reach  its  highest  point  till  three  hours  after  the  Moon  has 
gone  over  the  spot.  This  is  imputed  to  the  law  of  inertia,  or  the 
tendency  which  everything  has  to  remain  in  the  condition  in 
which  it  is  placed.  When  this  inertia  is  overcome,  the  waters  go 
on  rising  until  another  counteracting  influence  causes  them  to 
abate.  The  periodical  return  of  the  tides  tends  very  much  to 
confirm  this  theory  of  the  Moon's  agency.  It  was  said  that  two 
whole  tides  occupy  24  hours  and  50  minutes  ;  this  is  exactly  the 
period  required  for  the  Earth  to  be  brought  into  the  same  posi- 
tion with  respect  to  the  Moon  from  any  given  time;  she,  \\hile 
the  Earth  has  rotated  in  24  hours,  having  traversed  a  2Qth  part 
of  her  orbit. 

32.  The  Zodiac.  For  practical  purposes,  astronomers  consider 
the  starry  heavens  as  a  vast  concave  encircling  the  sun  at  an 
equal  distance  all  round.  For  the  convenience  of  studying 
astronomy,  they  have  imagined  a  horizontal  line  to  be  drawn 
across  this  concave,  passing  through  the  Sun's  center  from  east 
to  west.  This  is  termed  the  equator,  because  it  separates  the 
celestial  sphere  into  two  equal  halves,  the  upper  one  of  which  is 
called  the  northern  hemisphere,  and  the  lower  one  the  southern 
hemisphere.  The  planetary  bodies,  the  Earth  included,  do  not 
travel,  as  already  shown  (par.  24),  in  the  direction  of  the 
horizontal  line,  but  inclined  a  little  from  it,  forming  in  their 
orbit  the  ecliptic  circle.  A  large  belt  has  therefore  been  supposed 
to  be  drawn  on  the  heavens,  of  sufficient  breadth  to  include  the 
orbits  of  all  the  planets.  This  imaginary  belt,  which  is  studded 
with  stars,  is  known  as  the  zodiac.  Directly  along  its  center 


O i * TLIXES  OF  AS TROXOM  Y.  6 1 

lies  the  Earth's  path,  and  on  either  side  of  this,  and  sometimes 
crossing  it,  the  other  planets  roll  onwards  in  their  appointed 
courses.  To  form  a  conception  of  the  space  occupied  by  the 
zodiac,  it  is  necessary  to  be  acquainted  with  the  artificial  di- 
visions of  the  firmament. 

33.  Divisions  of  the  Celestial  Sphere.     The  vast  ethereal  con- 
cave before  mentioned,  has  been  divided  into  360  equal  parts,  or 
segments  of  a  circle,  called  degrees,  180  of  which  are  on  each 
side  of  the  equator,  north  and  south.     In  conjunction    with  the 
equatorial  line,  another  imaginary  line,  passing  perpendicularly 
through   the  Sun  and   starry    firmament,    divides   the   celestial 
globe  into  four  quarters,  each  of  which  is  thus  composed  of  90 
degrees ;    a   degree   is    subdivided   into   60  equal   parts,   called 
seconds.       These    divisions    of    the    circle    are    thus    denoted, 
8*  15'  30",  signifying  8  degrees,   15  minutes,  30  seconds.     The 
space  allotted  to  the  zodiac,    in  which   the   planets  revolve,    is 
about  16  degrees,  that  is,  8  degrees  on  each  side  of  the  ecliptic, 
or  the  path  traveled  by  our  globe.      Its  uses  are  to  determine  the 
position  of  the  Earth,  or  any  planet,  and   to  exhibit  the  altitude 
and  declination  of  a  star  at  any  specified  time,  these  being  all 
calculated  with  reference  to  the  ecliptic  line. 

34.  Signs  of  the  Zodiac.     The  imaginary  belt  or  ring  already 
spoken  of,  is  divided  into  twelve  equal  portions,  each  containing 
30  degrees,  called  the  signs  of  the  zodiac.     Three  of  them   are 
respectively   in  the   northern,    eastern,    southern,   and   western 
quarters  ;  and  to  distinguish  them,  they  have  received  a  nomen- 
clature from  a  fancied  resemblance  which  the  stars  lying  among 
them,  seemed   to   bear   to   some   terrestrial   object.     Thus,  one 
group  of  stars   was  supposed  to  bear  some  resemblance  to  the 
outline  of  a  ram  ;    hence  that  part  of  the  zodiac  lying  imme- 
diately beneath  the  group  was  named  the  Ram,  and  so  on.      The 
names  of  the  twelve  signs,  in  Latin   and  English,  are  as  follow  : 
Aries,  the   ram;    Taurus,  the   bull;    Gemini,  the  twins;    Cancer, 
the  crab;   Leo,  the  lion;  Virgo,  the  virgin;  Libra,  the  balance; 
Scorpio,  the  scorpion;  Sagittarius,  the  archer;  Capricornus,  the 
goat;   Aquarius,    the  water   bearer;  and  Pisces,    the   fish.     The 
Earth  passes  through  one  of  these  signs  every  month. 

35.  The  Seasons.     The  phenomena  of  the  seasons  conclusively 


62  0 U TLIXES  OF  AS TKOXOM Y. 

establish  the  main  facts  of  astronomy  ;  they  are  precisely  such 
as  would  result,  reasoning  from  first  principles,  assuming  the 
figure,  aspects,  and  motions  of  the  heavenly  bodies  to  be  what 
they  really  are.  Upon  no  other  theory  than  the  true  one  could 
they  be  intelligibly  and  rationally  demonstrated,  and  from  the 
progress  of  modern  sciences  they  are  capable  of  a  simple  and 
beautiful  explanation.  The  chief  distinguishing  characteristics 
of  the  seasons  consist  in  the  various  degrees  of  temperaiure 
and  light.  The  cause  of  the  variations  with  respect  to  the  light, 
is  shown  in  par.  25.  The  cause  of  the  thermal  diversity  is  very 
similar.  As  light  depends  upon  the  existence  and  presence  of 
the  solar  beams,  so  does  heat.  There  is,  however,  this  important 
difference  between  them  ;  light,  when  absorbed  is  suffocated, 
and  hence,  is  not  perceptible  Icng  after  the  absence  of  the  light- 
giving  body.  It  is  otherwise  with  heat;  this,  when  absorbed,  is 
retained  for  some  time,  and  is  given  off  by  radiation,  hence,  the 
warmth  of  night  sometimes  equals,  and  even  exceeds,  that  of 
day.  This,  indeed,  is  a  wise  provision  of  the  Creator;  for  were 
there  a  sudden  and  abrupt  transition  from  the  glowing  and 
fructifying  warmth  of  day  to  a  cold  temperature  at  night,  vege- 
tation would  be  destroyed,  and  the  autumnal  fruits  would 
perish,  for  cold  is  uncongenial  to  their  perfection. 

36.  Causes  of  the  Variations  of  Temperature.  By  variations  we 
do  not  mean  those  finer  shades  of  heat  and  cold  which  depend 
greatly  upon  atmospheric  conditions,  but  those  larger  and  more 
general  diversities  which  originate  from  the  mutual  aspects  of 
the  Sun  and  Earth.  The  Earth  passing  along  the  central  line  of 
the  zodiac  (par.  32),  completes  her  periodical  course  in  twelve 
calendar  months,  during  which  time  she  has  experienced  all  her 
thermal  vicissitudes  from  the  lowest  degree  of  cold  to  the  highest 
degree  of  heat.  Starting  from  that  portion  of  the  zodiac  marked 
as  Libra,  on  the  2ist  of  March,  when  the  spring  quarter  com- 
mences, she  progresses  through  Scorpio  and  Sagittarius  to  the 
first  point  of  Capricornus,  when  the  spring  quarter  terminates, 
and  the  summer  quarter  begins  on  the  2ist  of  June.  She  then 
travels  through  three  more  entire  signs  of  the  zodiac,  constitut- 
ing the  summer  quarter,  and  arrives  on  the  2ist  of  September  at 
the  first  point  of  Aries,  when  the  autumnal  quarter  is  entered. 


0 UT LINES  OF  AS TRONOM Y.  63 

Passing  through  three  signs  more,  and  coming  to  Cancer,  the 
autumn  is  completed,  and  -winter  commences  on  the  2ist  of  De- 
cember. Three  other  signs  yet  remain  to  be  traversed,  which, 
when  accomplished,  brings  her  to  Libra,  the  point  whence  she 
started.  Astronomers  generally  speak  of  the  Earth's  progress 
according  to  the  apparent  path  of  the  Sun  through  the  starry 
sphere;  they  then  commence  the  annual  course  with  the  point 
Aries,  because  that  is  the  sign  of  the  zodiac  in  which  the  Sun 
appears  to  be  located  when  the  Earth  begins  her  journey  at  the 
commencement  of  spring.  There  is,  however,  no  absolute  neces- 
sity for  this  We  have,  therefore,  begun  with  the  more  natural 
because  actual,  position  of  the  Earth  in  the  point  of  Libra.  Now, 
although  this  is  the  actual  progression  of  the  globe  along  the 
wide  extended  fields  of  ether  through  which  her  path  lies,  giving 
rise  to  that  beautiful  succession  of  seasons  which  is  so  admirably 
adapted  to  the  requirements  of  a  terrestial  world,  it  must  not  be 
supposed  that  the  whole  Earth  is  at  any  one  time  in  the  enjoy- 
ment of  spring,  and  at  another  period  immersed  in  the  depths  of 
winter,  etc.  No  ;  from  the  combined  effect  of  the  inclination  of 
her  axis,  and  her  annual  progress  round  the  Sun,  the  opposite 
seasons  of  summer  and  winter,  are  experienced  at  the  same  time 
in  the  northern  and  southern  hemisphere. 

37.  During  its  annual  revolution,  the  Earth  gyrates  in  such 
a  manner  as  always  to  have  the  Sun  vertical  in  some  part  of  the 
ecliptic;  that  is,  the  solar  rays  always  strike  some  point  of  her 
surface  embraced  within  the  limit-  of  the  ecliptic,  in  a  perpen- 
dicular direction  ;  the  space  so  inclosed  is  therefore  called  the 
torrid  zone.  It  extends  to  23  1-2  degrees  north  and  south  of  the 
equator.  The  day  and  night  within  this  boundary  are  of  nearly 
equal  duration  all  the  year  round,  and  the  temperature  is  main- 
tained at  pretty  nearly  an  equal  state.  The  two  circles  at  the 
poles  are  termed  frigid  zones,  the  word  zcne,  from  the  Greek, 
signifying  a  belt,  and  frigid,  cold  (as  torrid  signifies  burning  or 
scorching),  because  in  these  regions  the  greatest  cold  prevails. 
They  comprise  a  space  around  each  pole  of  23  j£  degrees.  The 
lines  which  bound  the  ecliptic  are  named  the  tropics,  after  a  Greek 
word  which  means  to  turn  or  change,  because  this  mark  points 
out  that  the  Earth  has  gained  her  highest  and  lowest  positions 


64  O  U TLIXES  OF  A  S TROXOM  Y. 

respectively,  and  thence  begins  to  ascend  and  descend.  The 
spaces  between  the  frigid  zones  and  the  tropics  are  called  the 
north  and  south  temperate  zones,  because  in  the  regions  lying  within 
these  circles,  the  heat  is  never  very  intense,  the  sun's  rays  shin- 
ing obliquely  upon  them.  The  numbers  round  the  circle  fin  a 
map  of  the  Earth)  indicate  the  360  degrees  into  which  the  circum- 
ference of  the  globe  has  been  divided  ;  the  equatorial  line  girding 
the  Earth,  has  also  been  divided  into  a  similar  number  of  de- 
grees ;  of  these  we  shall  have  occasion  to  speak  more  fully  when 
treating  of  the  natural  divisic  ns  of  lime.  It  will  be  seen  that 
there  is  at  all  times  a  decrease  of  temperature,  from  the  equator 
towards  each  pole,  but  the  variable  intensity  of  heat  and  cold  is 
regulated  by  the  Earth's  progress  in  her  periodical  orbit. 

38.  Another  point  necessary  to  be  mentioned,  is  the  irregu- 
larity of  the  Earth's  distance  from  the  Sun.  She  does  not  travel 
round  the  Sun  in  a  perfect  circle,  but  her  orbit  is  that  of  an 
ellipse,  in  which  the  Sun  is  located  nearer  to  one  end  than  the 
other.  Our  winter  occurs  when  the  Earth  is  nearest  to  the  Sun. 
The  reason  why  we  do  not  experience  a  greater  amount  of  heat 
at  that  season,  is  because  the  portion  of  the  globe  upon  which 
Great  Britain  is  situated  is  turned  so  much  aslant  from  the  Sun 
as  to  catch  his  lays  but  very  indirectly.  But  it  is  found  that  the 
southern  hemisphere  which  is  then  so  immediately  receptive  of 
the  solar  beams  does  not  experience  a  greater  degree  of  heat 
than  the  ncrth  when  similarly  receptive  at  a  much  greater  dis- 
tance. How  is  this  to  be  explained?  Simply  thus  :  as  the  Earth 
approaches  this  portion  of  her  orbit  she  gradually  accelerates 
her  speed,  and  goes  on  increasing  it  till  she  arrives  at  the  turn- 
ing point,  when  she  begins  to  slacken  until  she  comes  to  her 
mean  rate,  hence  it  is  found  that  the  winter  half-year  is  accom- 
plished in  eight  days  less  than  the  summer  half.  By  this  in- 
creased rate  of  velocity,  the  Sun  is  prevented  from  being  so  long 
above  the  horizon  as  he  otherwise  would  be,  and  thus  his  heat- 
dispensing  power  is  proportionately  diminished.  Were  it  not  so, 
it  is  supposed  that  the  southern  portion  of  the  globe  during  our 
winter  season,  would  be  quite  unfit  for  the  purposes  of  life. 
That  the  increased  velocity  diminishes  the  reception  of  heat, 
may  be  made  familiar  to  any  one  by  the  aid  of  a  common  ther- 


O U TLIXES  OF  A  S  TROXOM  Y.  65 

mometer.  Let  it  be  attached  to  a  cylinder  and  turned  slowly 
round  before  a  large  fire,  noting  the  degree  of  heat;  then  let  it 
be  turned  swiftly,  and  it  will  be  found  that  the  temperature  di- 
minishes in  an  equal  ratio  to  the  increased  velocity.  This  heai- 
rtceiving  process  is  very  different  from  the  heat-prc during  process ; 
for,  in  the  latter,  the  more  rapid  the  motion,  the  higher  is  the 
temperature  raised.  The  effect  would  be  the  same  if  the  ther- 
mometer were  carried  round  the  fire,  to  represent  the  earth's 
orbital  motion. 

39.  We  may  here  for  a  moment  pause  to  moralize.  The  sea- 
sons have  been  wisely  ordained.  They  minister  not  only  to 
man's  outward  necessities,  but  also  to  his  inner  being, — to  the 
activities  of  thought  and  affection.  They  speak  of  an  overruling 
Providence,  whose  guardianship  extends  to  the  meanest  of 
created  beings,  whose  laws  are  immutable  and  all-pervading; 
they  speak  of  order,  "  heaven's  first  law,"  of  equity  and  bene- 
ficence ;  for  in  nature  there  is  no  fortuitous  or  chance  occurrence, 
no  capricious  partiality  or  selfishness.  The  uses  intended  by  the 
succession  of  the  seasons  are  of  universal  application  ;  they  exist 
for  all.  Poets  and  philosophers  have  thought  upon  this  subject, 
and  given  utterance  to  their  musings.  Some  have  traced  an 
analogy  between  the  seasons  and  the  four  general  periods  of 
human  life,  comparing  spring  to  childhood,  summer  to  youth, 
autumn  to  manhood,  and  winter  to  old  age.  There  is  indeed  a 
joyousness  and  freshness  about  the  spring  which  will  well  typify 
the  mirthfulness  and  bouyancy  of  childhood's  happy  state,  while 
in  the  activity  and  ardor  of  the  youthful  temperament  there  is 
something  of  the  busy  life  and  genial  warmth  of  summer. 
There  is  also  in  the  man,  with  his  increased  capabilities  for  use- 
fulness, something  akin  to  the  richly  laden  autumn,  with  its 
plenteous  stores  of  mellow  fruit  and  grain,  proffered  to  the  will- 
ing and  receptive  hand.  And  in  winter,  too,  the  season  of  decay 
and  apparent  death,  the  time  of  withered  leaves  and  darksome 
clouds,  we  may  trace  a  resemblance  to  the  last  period  of  mun- 
dane life,  when  the  powers  of  nature  are  fast  waning,  the  natural 
energies  are  dormant,  exterior  adornments  lose  their  fascination 
and  attractiveness  and  all  outer  things  are  much  obscured,  and 
there  is  general  preparation  for  a  season  of  resuscitation,  in  a 


66  OUTLINES  OF  AS TRONOM Y. 

new  world  of  life  and  beauty.  Others  admitting  this  exterior 
analogy  between  the  seasons  and  the  stages  of  man's  earthly 
existence,  go  deeper  and  descry  a  correspondence  between  the 
uses  of  the  seasons  and  the  interior  states  of  mental  being, 
states  of  affection,  and  variations  of  both.  Thus,  a  wintry 
mental  state,  say  they,  is  that  condition  of  the  mind  in  which 
the  affections  are  cold,  because  not  warmed  by  love  to  God  and 
man,  and  the  thoughts  are  obscured  because  not  illuminated  by 
rays  of  genuine  wisdom  ;  thus  the  mind  is  averted  from  the  only 
source  of  spiritual  light  and  heat,  and,  in  reference  to  the  Divine 
Being,  is  torpid.  Again,  it  is  springtime  with  the  soul  when  it 
is  awakened  from  its  dormant  state,  when  the  affections  begin  to 
bud  forth  under  the  influence  of  new  life,  when  the  mind  turns 
toward  the  Creator  of  all  good,  and  is  disposed  to  receive  His 
light-imparting  instructions  ;  when,  like  nature,  it  is  quickening 
for  the  coming  produce.  In  its  summer  season  it  is  still  more 
turned  to  the  heavenly  source  and  parent  of  light,  and  is  much 
more  receptive  of  His  vivifying  love  and  illustrating  wisdom, 
whence  proceed  the  fruits  of  faith,  and  the  beatifying  works  of 
charity;  and  then  succeeds  its  autumnal  state,  in  which  the 
heart  overflows  with  gratitude  to  God  and  love  to  man,  its  fruits 
are  mellow,  ripened  by'celestial  heat,  and  matured  by  experience. 
This  is  the  soul's  harvest-time.  Happy  all  who  are  in  such  a 
state. 

40.  General  Divisions  of  Time.     Time   is  duration,  which   can 
only  be  measured  by  motion  ;  if  all  things  were  stationary  and 
inert,  time  could  have  no  existence.      It  is  of  three  kinds:  Mean 
or  equal,  that  measured  by  clocks  ;  true  or  solar,  that  indicated  by 
the  apparent  movement  of  the  Sun  ;  and  sidereal,  or  that  which 
results  from  the  position   of   the  fixed  stars.      The  first,  which  is 
a  division  of  the  day  into  24  hours,  is  purely  conventional,  but  at 
the  same  time  well-adapted  for  practical  purposes.       The  second 
and  third  are  natural. 

41.  Sidereal  7'ime.      This  is  determined  by  the  earth's  relative 
position  to  any  fixed  star.     Although  it  is  customary  to  say  that 
the  Earth  rotates  upon  its  axis  in  24  hours,  this  is  incorrect ;  the 
fact  is,  it  performs  its  entire  revolution  in  23  hours,  56  minutes 
4  seconds.     The  fixed  stars  being  located  at  an  immense  distance 


OUTLINES  OF  A STRONOM  Y.  67 

from  the  Earth,  its  orbit  is  so  small  in  comparison  with  their 
remoteness,  that,  in  respe.ct  to  them,  it  would  seem  to  have  no 
other  motion  than  its  diurnal  one;  hence  it  is  thai  any  one  of 
them  which  may  be  selected,  will  appear  to  rise  regularly  3  minutes 
56  seconds  earlier  every  day  ;  this  being  the  difference  between 
the  sidereal  day  and  that  of  24  hours.  Now  this  daily  difference 
amounts,  in  the  course  of  a  year,  to  almost  another  sideral  day; 
consequently,  when  the  Earth  has  performed  an  entire  revolution 
round  the  Sun,  and  arrived  at  the  point  in  the  heavens  from 
which  she  commenced  her  .annual  journey,  in  a  period  of  365 
days,  8  hours,  9  minutes,  II  seconds  (reckoning  24  hours  to  a 
day),  she  has  made  366  entire  revolutions  upon  her  axis,  thus 
making  the  sidereal  year  to  contain  366  days.  Although  this  is 
the  most  precise  method  of  computing  time,  on  account  of  the 
stars  not  shifting  their  positions  in  reference  to  the  Earth,  as  the 
Sun  does,  it  is,  however,  not  so  convenient,  nor  practical,  as  the 
solar  measurement ;  the  latter  is,  therefore,  that  generally 
adopted.  Let  us  then  see  in  what  this  differs  from  the  former. 

42  Solar  Time.  This,  which  is  sometimes  called  astro- 
nomical time,  is  reckoned  from  noon  to  noon,  and  would 
perfectly  co-incide  with  siderial  time  if  the  Earth  had  no  other 
movement  than  the  axillary  ;  but  in  pursuing  its  annual  course, 
it  is  propelled  along  its  circuit  at  the  rate  of  nearly  1,600,000 
miles  per  day.  This  must  produce  a  considerable  difference 
between  the  solar  and  sideral  day,  as  some  portion  of  time  must 
necessarily  elapse  after  the  Earth  has  completed  its  rotation, 
before  any  particular  spot  upon  its  surface  would  come  under 
the  mid-day  Sun,  as  it  was  the  day  previous.  Such  we  find  to 
be  the  case,  and  hence  true  solar  time  varies  very  little  from 
that  of  the  clocks,  the  greatest  difference  never  exceeding  half  a 
minute  in  the  24  hours.  At  four  periods  of  the  year  they  are 
similar,  hence  the  application  of  the  term  mean  time.  Owing  to 
this  slight  variation,  the  solar  mid-day,  which  is  determined  by 
the  Sun's  having  attained  its  highest  point  in  the  heavens,  is 
sometimes  16^  minutes  earlier,  and  sometimes  14^  minutes 
later,  than  12  o'clock  mean  time.  The  clock  is  then  said  to  be  so 
many  minutes  slower  or  faster  than  the  Sun.  These  are  the  extreme 
points  of  variation. 


68  0 UTLINES  OF  AS TRONOM Y. 

43.  Cause  of  the  Difference  of  Time  in  Different  Parts  of  the 
World.  An  observer  upon  a  high  eminence  will  find  his  vision 
bounded  in  every  direction  by  the  sky  :  the  sky-line  which  thus 
bounds  his  vision  is  called  the  horizon.  The  apparent  path  of 
the  Sun  is  from  the  east  to  the  west.  A  line  drawn  over-head, 
midway  between  these  quarters,  is  called  the  meridian,  and  when 
the  Sun  has  arrived  at  this  point,  he  has  attained  his  highest 
position,  and  is  consequently  half  way  across  the  horizon,  and  is 
said  to  be  in  the  meridian  :  this  determines  mid-day.  At  all 
other  places,  the  time  varies  from  noon  to  midnight,  and  from 
midnight  to  mid-day.  To  render  this  intelligible,  certain  lines 
have  been  drawn  on  artificial  globes,  in  a  direction  from  north  to 
south,  called  meridians;  when  the  Sun  is  immediately  over  one 
of  these  lines,  it  is  then  mid-day  at  ail  places  through  which 
the  meridian  passes.  Now  the  Earth  being  a  revolving  globe, 
with  its'surface  divided  into  360  equal  parts,  and  the  day  being 
divided  into  24  hours,  it  follows  that  15  degrees,  must  pass  under 
the  mid-day  Sun  every  hour,  for  360  divided  by  24  gives  15  as  a 
quotient,  consequently  when  it  is  12  o'clock  at  noon  at  any 
particular  place,  say  London,  it  is  one  hour  before  mid-day  or  n 
o'clock  at  any  spot  15  degrees  west  of  London,  and  one  hour 
after  mid-day  or  I  o'clock  at  any  place  15  degrees  east;  as,  for 
instance  Berlin.  And  so  traveling  round  the  globe  in  a  westerly 
direction,  with  the  watch  set  to  London  time,  we  should  find  the 
clocks  an  hour  later  for  every  15  degrees  we  proceeded. 

A  degree  at  the  equator  is  60  geographical,  or  about  69 
English  miles.  Of  course,  as  the  Earth  is  globular,  the  degree 
diminishes  in  proportion  as  we  approach  either  the  northern  or 
southern  regions;  therefore,  in  traveling  a  given  distance  in  an 
easterly  or  westerly  direction,  either  north  or  south  of  the 
equator,  a  greater  variation  of  time  would  be  observable  than 
upon  the  equator  itself  The  meridians  are  also  employed  by 
geographers  to  compute  distances,  the  distance,  east  or  west, 
being  called  so  many  degrees  east  or  west  longitude;  and  north 
or  south,  so  many  degrees  north  or  south  latitude.  For  the  pur- 
poses of  precise  measurement,  each  degree  is  divided  into  60 
minutes,  and  each  minute  into  60  seconds,  as  in  the  celestial 
sphere,  (par.  33.) 


O  U  TLI.VES  OF  A  S  TRONOU  Y.  69 

44.  The    Calendar.     The    calendar    is    a    table    of    the    days, 
weeks,  months,  etc.;  and  was  instituted  with  a  view  of  reducing 
time  to  something  like  a  standard.       The  Roman  calendar,  from 
which  ours  is  derived,  at  first  divided  the  year  into  ten  months, 
the  total  number  of  days  in  which  amounted  to  only    304.     It 
was  soon  discovered  that  the  civil  year,  as  thus  constituted,  was 
shorter  than    the   solar  year,  marked  by   the  succession  of  the 
seasons;  two  additional  months  were  then  added  to   the   year, 
and  the  12  months  were  made  to  consist  of  29  and  30  days  each 
alternately,  thus  comprising  355  days;  and  that  the  civil  might 
equal    the    solar   year,    a    month    was  added    every  two   years. 
This    was    found    extremely     inconvenient,     wherefore,    Julius 
Caesar  undertook  to  reform  the  calendar,  and  made  the  year  to 
consist  of  365  days,  and,  to  bring  in  the  surplus  hours  added  a 
day  to  every  fourth  year,  which  was  in  consequence  called  leap- 
year.     By  this  arrangement  there  is  an  excess  of  a  few  minutes 
annually,  which,  in  the  course  of  1,600  years,  amounted  to  ten 
days.      Pope  Gregory  XIII,  in  order  to  remedy  this,  decreed  that 
the    366th  day  of  every  leap  year,  which  commenced  a  century 
should    be    omitted,    excepting    that   of    every    fourth    century, 
which  would  compensate  for  the  slight  loss    under  the   former 
arrangement        To  remove  the  loss  which  had  been  already  sus- 
tained, from  the  time  of  Julius  Caesar  till  1582,  ten  days  were  at 
once   struck   off  from    the   calendar,    thus   originating   what   is 
termed  New  Style.     The  New  Style  was  not  adopted  in  England 
till  1752,  when,  to  make  up  for  the  accumulated  loss,  eleven  days 
were  struck  off,  and  the  day  following,  the  2nd  of  September,  was 
called  the  I4th.     Russia  and  Greece  are  now  the  only  countries 
in    Europe    which    retain  the  old  style:  the  difference   between 
their  time  and  ours    amounts  now  to  12  days.     Our  civil  year 
still  exceeds  the  true  one  by  a  small  fraction;  to  rectify  this  it  is 
necessary  that   another   leap-year   should    be   omitted    in   every 
4,000  years. 

45.  Origin   of   the   Names   of   the   Months. —  January   was  so 
named  in  honor  of  an  idol  called  Janus,  which  was  worshiped 
by  the  Romans,    and    whose   temple  was  kept  open  during  the 
time  of  war,  and  closed  in  times  of  peace.     It  was  fixed  as  the 
first   month  by  Numa    Pompilius.     February  is   so   called    from 


70  O U TUNES  OF  AS TRONOM Y. 

Februa,  the  name  of  a  feast  held  by  the  Romans,  in  which  they 
offered  expiatory  sacrifices  in  behalf  of  deceased  persons.  Feb- 
ruus  is  the  Latin  for  Pluto,  the  god  of  the  infernal  regions. 
March,  which,  before  the  time  of  Pompilius,  was  considered  the 
first  month  of  the  year,  was  named  in  honor  of  Mars,  the  god  of 
war.  April  i1-,  derived  from  the  Latin  Aprilis.  iromaperio,  I  open, 
and  is  supposed  to  have  been  given  to  this  month  because  at 
this  season  the  Earth  opens  her  bosom,  as  it  were,  for  the  pro- 
duction of  vegetables  and  flowers,  fruits  and  farinacia,  etc. 
May  is  generally  considered  to  have  received  its  name  from  Maia, 
the  mother  of  Mercury,  who,  Roman  legends  affirm,  was  sacrificed 
on  the  first  day,  and  to  whom  oblations  were  to  be  offered  dur- 
ing the  month.  June.  There  are  two  opinions  respecting  the 
origin  of  this  name.  Some  say  that  it  is  from  Junius,  because 
this  month  was  dedicated  to  the  service  of  Juno,  a  heathen 
goddess;  others  that  it  is  iromjuniores,  the  name  given  to  the 
young  men  who  had  fought  for  their  country;  certain  feasts  in 
honor  of  them  being  held  during  this  month.  July,  from  the 
Latin  Julius,  was  thus  named  in  honor  of  Julius  Caesar.  Before 
his  time  it  was  known  as  Quintilis,  that  is  the  fifth  month, 
reckoning  from  March.  August  is  from  Augustus,  in  honor  of 
Augustus  Caesar.  It  was  formerly  called  Sextilis,  the  sixth 
month.  September  is  from  septem,  seven,  it  being  the  seventh 
month  from  March.  October  is  from  Octo,  eight,  the  eighth  month. 
November  is  derived  from  Novem,  nine,  as  this  was  the  ninth 
month.  December  is  from  decent,  ten,  which  was  the  tenth  month 
from  March. 

46.  Origin  of  the  Names  of  the  Days. — The  names  of  the  days 
are  all  of  Saxon  origin.  Sunday  is  so  named  from  a  Saxon  idol 
of  the  sun  which  was  worshipped  on  this  day.  Monday  was  a 
day  set  apart  for  the  adoration  of  an  idol  of  the  moon,  and  was 
originally  called  Moonday.  Tuesday  had  its  origin  in  the  Saxon 
word  Tuisco,  the  name  of  a  hero  who  was  venerated  by  the 
ancient  Germans  as  the  founder  of  their  nation.  They  be- 
lieved that  under  his  auspices  they  were  safely  conducted 
from  the  confusion  which  followed  the  building  of  the 
tower  of  Babel.  Wednesday  is  so  called  in  honor  of  Woden,  the 
Saxon  god  of  battle.  It  was  at  first  Wodensday,  and  eventually 


O U TLI.VES  OF  AS TRONO.M Y.  71 

became  abbreviated  to  Wednesday.  Thursday  is  from  Thor,  an 
idol  adored  by  the  Teutonic  people  as  the  god  of  thunder. 
His  worship  was  celebrated  on  this  day.  The  transition  from 
Thor's  day  to  Thursday  is  not  very  great.  Friday  \s  from  Friga  a 
Saxon  idol  representing  both  sexes.  He  was  the  supposed  giver 
of  peace  and  plenty,  and  the  inspirer  of  the  love  of  the  sexes. 
This  day  was  dedicated  to  him.  Saturday  is  from  Seatfr,  an  idol 
who  was  supposed  to  control  the  productions  of  the  Earth,  to  in- 
spire the  Saxon  love  of  freedom,  and  to  promote  concord  and 
unity. 

47.  The  Sidereal  System.  Our  preceding  observations  have 
had  exclusive  reference  to  the  members  of  our  solar  system. 
\Ve  will  now  take  a  glance  at  the  regions  of  space  surrounding 
it.  It  must  be  obvious  to  all  that  the  few  bodies  already  de- 
scribed, form  but  a  very  small  fraction  of  the  starry  universe — 
of  that  portion  of  it,  rather,  which  is  visible  to  us ;  and  this, 
perhaps,  in  comparision  with  that  which  is  invisible,  is  as  a  drop 
to  the  ocean.  The  stars  visible  to  the  naked  eye  are  few  indeed 
compared  with  the  number  revealed  by  the  telescope ;  and  with 
every  increase  of  telescopic  power,  hosts  of  new  objects  are 
found  to  adorn  the  expanse  of  the  material  heavens ;  which,  but 
for  this  agency,  would  remain  forever  hidden  from  our  view. 
The  discovery  of  distant  and  still  more  distant  members  of  the 
starry  heavens,  may  go  on  as  science  advances,  but,  shall  we  ever 
be  able  to  say  that  we  have  penetrated  to  the  boundaries  of 
space  ?  The  members  of  the  sidereal  system  are  innumerable 
and  their  distances  inconceivable.  Athough  incapable  of  cal- 
culation and  measurement,  some  of  them  present  features  which 
show  that  they  are  of  a  kindred  nature  to  our  sun.  If  so — if  they 
are  self-luminous  orbs,  for  what  purpose,  as  it  respects  our- 
selves, do  they  shine.  This  question  is  answered  by  a  supposi- 
tion, not  entirely  destitute  of  evidence,  that  each  sun  is  the 
center  of  a  system  of  revolving  worlds,  of  which  our  world  and 
our  solar  system  will  afford  a  type.  The  evidence  upon  which 
this  supposition,  at  present,  rests,  independently  of  analogical 
reasoning,  is  the  long-observed  phenomena  of  stellar  changes. 
Many  stars  have  been  found  to  vary  considerably  in  luster;  at 
one  time  attaining  to  a  certain  degree  of  brightness,  and  then 


72  OUTLINES  OF  AS TRONOM Y. 

becoming  comparatively  dim  ;  and  these  variations  are  found 
to  observe  regular  periods.  Thus  the  changes  in  one  star  occupy 
rather  less  than  three  days.  Another  passes  through  its  suc- 
cession of  changes  in  a  period  of  six  days  and  nine  hours ;  while 
another  decreases  in  brilliancy  until  it  gradually  becomes  in- 
visible, and  then  as  gradually  resumes  its  original  splendor, 
occupying  in  these  changes,  eighteen  years.  Many  more  might 
be  enumerated,  but  these  are  sufficient  to  illustrate  the  phe- 
nomena. Now  as  the  position  of  these  stars  in  the  heavens 
remains  the  same  during  all  their  changes,  no  orbital  motion  or 
progression  in  space  is  adequate  to  account  for  their  irregular 
brightness.  The  most  reasonable  conclusion,  therefore,  appears 
to  be,  that  certain  opaque  bodies,  of  great  magnitude,  are  re- 
volving round  the  stars,  and  according  to  their  position  in  their 
orbits,  sometimes  intercept  a  portion  of  their  light,  and  some- 
times entirely  eclipse  them.  An  eminent  astronomer  of  the 
present  day  believes  that  he  has  observed  attendant  bodies  con- 
tiguous to  some  of  the  brighter  stars,  shining,  probably,  by 
reflected  light. 

48.  The  Fixed  Stars.  The  most  obvious  feature  distinguish- 
ing the  stars,  is  their  relative  brilliancy.  Some  are  remarkably 
bright,  while  others  are  very  faint.  From  this  circumstance, 
astronomers  have  been  enabled  to  classify  them  into  different 
orders,  and  speak  of  them  as  stars  of  the  first,  second,  and  third, 
up  to  the  sixteenth  magnitude.  There  are  about  24  of  the 
brightest  stars  included  in  the  first  magnitude,  between  50  and 
60  of  the  second  magnitude  ;  and  the  third  comprises  about  200  of 
smaller  and  less  brilliant  ones.  The  number  of  stars  that  have 
been  registered,  as  far  as  the  seventh  magnitude,  amounts  to 
nearly  15,000.  Those  of  the  fifth  are  the  smallest  that  can 
generally  be  seen  by  the  naked  eye,  though  sometimes  on  a 
particularly  clear  night,  a  few  of  the  sixth  degree  may  be  in- 
distinctly seen.  The  stars  exhibit  not  only  a  different  degree, 
but  a  different  kind  of  luster.  Their  rays  differ  not  more  in 
intensity  than  in  kind.  One  shines  with  a  white  silvery  light, 
while  another  has  a  ruddy  glow.  Some  are  red,  others  green, 
or  yellow,  or  blue.  These  varieties  of  color  are,  perhaps,  not 
intrinsic  to  the  star,  but  are  the  result  of  optical  illusion.  Al- 


OUTLINES  OF  ASTRONOMY.  73 

though  it  is  customary  to  speak  of  the  stars  as  fixed^  yet  this  is 
not  strictly  correct  ;  for,  though  they  have  no  perceptible  motion, 
they  are  supposed  to  have  a  progressive  motion  through  space. 

4g.  Binary  Stars.  These  form  a  curious  and  numerous  class 
of  heavenly  bodies.  They  are  called  binary  or  double,  not 
merely  because  they  are  are  found  lying  close  to  each  other, 
but  trom  their  mutually  revolving  about  one  another,  in  regular 
orbits .  and  determinate  periods.  Their  nature  is,  at  present, 
involved  in  obscurity.  Above  four  thousand  have  already  been 
catalogued,  and  of  these,  several  have  been  subjected  to  obser- 
vation for  the  purpose  of  ascertaining  their  periods  and  orbits. 
Some  of  those  stars  which  appear  as  one  to  the  naked  eye,  are 
resolved  by  the  telescope  into  two  distinct  stars.  At  first,  they 
were  supposed  to  be  in  close  proximity,  or  that  one  was  far  be- 
hind the  other,  almost  in  a  right  line.  These  opinions  were  soon 
dispelled  by  the  application  of  telescopes  of  sufficient  power, 
which  showed  that  they  revolved  round  each  other.  Their  orbits 
appear  to  be  similar  to  those  prevailing  in  our  system,  namely, 
the  ecliptic. 

50.  The  Constellation.     When    prosecuting    researches   among 
the   stars,    great   difficulty   and    perplexity  were  frequently  oc- 
casioned by  the  want  of  recognized  points  to  guide  in  the  search. 
At  an  early  period,  astronomers  learned  this  from  experience, 
and  were  led  to  remove   these   sources  of  error,   by  conferring 
names  upon  certain  clusters  or  groups  of  stars,  and  by  delineat- 
ing them   upon   maps,  or  artificial  globes.     These   names  were 
generally  applied  from  a  fancied  resemblance  which  the  clusters 
bore  to  some  well-known   object.     Thus,  a  number  of  stars  are 
found  grouped  together  in  such  a  manner  as  to  suggest  the  out- 
line of  a    bear.     This  cluster   has,  therefore,   been  denominated 
the  Bear,  and  so  in   other   cases.     These  fanciful  groupings  are 
what  are  termed   constellations.      Their  chief  use  is  the  facility 
they  afford  for  correct  and   speedy  reference  to  any  particular 
part   of  the    heavens.     It    is,    therefore,    customary    among   as- 
tronomers, when  referring  to  the  locality  of  a  star,  to  say  that  it 
is  in  such  and  such  a  constellation. 

51.  The  Milky   Way.     As  a  relief  to  the  general  deep  blue 
which  the  sky  presents,  may  be  traced   a  whitish  lustrous  belt, 


74  OL'l 'LINES  OF  AS TRONOM Y. 

arching  the  whole  firmament,  about  eight  degrees  in  breadth, 
and  inclined  at  an  angle  of  about  sixty  degrees  to  the  ecliptic. 
This  broad  belt  has  been  called  the  Milky  Way,  from  its  milk- 
white  appearance.  It  passes  in  the  northern  hemisphere,  between 
the  horns  of  the  Bull  and  the  feet  of  the  Twins  ;  and  winds 
round,  in  the  southern  hemisphere,  between  the  Archer  and  the 
Scorpion.  Taking  a  hasty  glance  at  it,  nothing  is  perceived  but 
a  luminous  haze,  with  here  and  there  a  star  interspersed  ;  but  on 
close  observation  it  appears  studded  with  small  luminous  points. 
The  real  nature  of  the  Milky  Way  greatly  puzzled  the  ancient 
philosophers,  some  ot  whom  imagined  it  was  celestial  fire  beam- 
ing through  the  clefts  of  the  solid  universe.  Modern  researches 
have  set  the  matter  at  rest  by  demonstrating,  with  the  aid  of 
.  strong  magnifying  power,  that  it  is  composed  of  an  innumerable 
host  of  individual  stars.  So  thickly  are  they  crowded  together 
as  to  give  the  appearance  of  glittering  dust.  This  star-dust, 
each  grain  of  which,  it  must  be  remembered,  is  a  separate  and 
individual  star,  lies  at  an  immeasurable  distance.  No  mode  of 
measurement  hitherto  adopted,  can  determine  its  remoteness. 
To  give  some  idea  of  the  distance  of  the  stars  composing  the 
Milky  Way,  it  may  be  stated  that  the  distance  of  some  of  the 
fixed  stars  has  been  ascertained  to  be  at  least  eighty  billion  (that 
is,  eighty  million  million)  miles; — a  space  which  light,  the 
swiftest  traveler  with  which  we  are  acquainted,  would  occupy 
thirteen  years  in  traversing,  at  a  speed  of  200,000  miles  per 
second  ; — and  that  these  stars  are  much  nearer  to  us  than  those 
of  the  Milky  Way.  The  brightest  stars  are  at  approximately 
measurable  distances,  but  those  in  the  Milky  Way  are  at  im- 
measurable distances. 

52.  The  Nebula.  Who  that  has  looked  out  attentively  at  the 
clear  blue  sky,  at  night,  has  not  observed  a  number  of  cloud-like 
patches  of  a  rather  faint  or  misty  light.  They  form  a  pleasing 
contrast  to  the  dark  ground  of  the  firmament,  and  appear  as  so 
many  radiant  spots,  illuminated  by  some  far  distant  bodies. 
These  patches,  which  are  of  every  variety  of  figure,  and  of 
different  degree  of  intensity,  have  been  named  Nebulae,  a  word 
signifying  clouds.  Those  which  the  telescope  has  succeeded  in 
resolving,  have  been  found  to  consist  principally  of  clusters  of 


0 U TUNE S  OF  AS TR ONOM Y.  75 

countless  stars,  densely  packed  in  the  center,  and  gradually  di- 
minishing in  number  towards  the  circumference  of  the  nebulae. 
Besides  the  well-defined  stars,  a  vast  number  of  brilliant  points 
have  been  observed  interspersed,  which,  from  their  general  ap- 
pearance, have  also  been  termed  light-mist.  Great  interest  is 
manifested  in  the  observation  of  these  nebulae,  in  the  present 
day.  They  were,  for  some  time,  supposed  to  consist  of  light 
vapory  matter,  and  were  regarded  as  embryo  suns,  or  solar 
systems  in  a  state  of  formation,  This  opinion  is  now  nearly 
dispelled  by  the  application  of  extraordinary  telescopic  power. 
Judging  from  what  has  been  with  certainty  discovered,  it  is  sup- 
posed that  every  speck  of  the  light  mist  is  a  distinct  star — a  solar 
luminary, — the  independent  center  of  a  number  of  worlds.  What 
a  vast  conception  of  the  universe  does  this  idea  present?  How 
boundless  appear  the  realms  of  space,  when  masses  of  matter  so 
immense  in  size  as  those  distant  stars  must  be,  are  found  so  near 
to  each  other  as  to  appear  in  contact,  like  grains  of  sand  upon 
the  sea  shore,  while  the  spaces  between  them  must  exceed,  by 
thousands,  if  not  millions  of  times,  the  actual  bulk  of  each.  And 
yet  those  which  are  included  in  our  universe,  with  its  myriads  of 
suns,  and  attendant  worlds,  may  be  but  a  small  portion  of  the 
wide  creation  of  God.  What  lies  beyond  all  that  we  can  discern 
on  every  side,  we,  of  course,  cannot  conceive.  That  what  we  at 
present  witness,  is  all  that  exists,  it  would  be  presumptuous  to 
affirm  ;  and  much  more  so  to  assert  that  the  inhabitants  of  our 
globe  will  ever  behold  all  that  exists  in  the  wide  extended  range 
of  creation.  At  most,  we  can  enjoy  but  one  aspect  of  the  Creator's 
works, — can  view  only  that  portion  of  the  universe  which  is 
visible  from  the  stand-point  of  our  own  orbital  path  round 
our  own  sun  or  star.  We  know  that  we  are  surrounded 
by  "hosts"  of  sun-worlds — the  "hosts  of  heaven" — that 
support  still  more  numerous  hosts  of  earth-worlds,  but  how  far 
we  are  from  even  the  nearest,  the  highest  powers  of  astronomical 
science  cannot  reveal  to  us.  We  only  know  that  they  are  all 
placed  at  such  immense  distances  from  us  in  the  depths  of  space, 
that  though  we  are  200  million  miles  nearer  to  some  particular 
stars,  at  any  given  period  of  the  year  than  we  are  six  months 
later,  not  the  slightest  difference  in  the  distance  is  discovered  on 


76  OU T LINES  OF  AS TRONOM Y. 

the  application  of  the  highest  telescopic  power  we  possess.  We 
know  that  we  are  encircled  by  the  Milky  Zone,  but  we  know  not 
what  is  going  on  on  the  other  side  of  it,  and  beyond  that  portion 
of  the  universe  which  lies  within  the  range  of  our  observation. 
Imagine  for  a  moment  that  we  were  placed  as  far  distant  from 
the  Milky  Way,  on  its  outside,  as  we  are  at  present  within,  and 
what  new  views  would  be  presented  to  our  sight.  \Ve  might 
then  discern  as  great  a  variety  of  new  celestial  objects,  as  far  as 
the  telescope-assisted  eye  could  reach,  as  those  with  which  we 
are  familiar  here.  The  thought  is  elevating,  and  should  lead  us 
upward  to  the  contemplation  of  an  Infinite  Creator.  In  this 
department  of  his  creation  we  have  vividly  presented  us  an 
i.v.age  of  his  infinity  and  eternity.  We  recognize  in  his  works  a 
sphere  of  operations  as  boundless  as  Himself,  the  Source  of  all. 
In  contemplating  these  effects  of  his  omnipotence,  we  should 
view  Him  as  a  perpetual  Creator.  As  a  Creator  he  is  infinite,  and 
an  infinite  Creator  cannot  be  other  than  a  perpetual  producer. 
There  can  be  no  cessation  to  his  operations.  The  same  almighty 
power  which,  in  the  beginning,  produced  one  world,  or  system 
of  worlds,  is,  doubtless,  ever  bringing  forth  more.  An  all-perfect 
Being  is  also  an  ever-active  one.  Let  man  humble  himself 
before  this  great  and  good  "  Father  of  all"  worlds  and  men,  and 
receive  with  meekness  those  soul-elevating  lessons  which  nature, 
in  this  her  grandest  aspect  teaches,  respecting  the  character  and 
destiny  of  humanity. 

53.  In  reference  to  the  stellar  orbs  that  compose  the  nebulae, 
we  would  ask,  in  the  eloquent  language  of  the  late  Dr.  Chalmers, 
"Shall  we  say,  of  these  vast  luminaries,  that  they  were  created 
in  vain.  Were  they  called  into  existence  for  no  other  purpose 
than  to  throw  a  fide  of  useless  splendor  over  the  solitudes  of 
immensity.  Our  sun  is  only  one  of  those  luminaries,  and  we 
know  he  has  worlds  in  his  train.  Why  should  we  strip  the  rest 
of  these  princely  attendants.  Why  may  not  each  of  them  be  the 
center  of  his  own  system,  and  give  light  to  his  own  worlds.  It  is 
true  that  we  see  them  not ;  but,  could  the  eye  of  man  take  its 
flight  into  those  distant  regions,  it  would  lose  sight  of  our  little 
world  before  it  reached  the  outer  limits  of  our  system. — the 
greater  planets  would  disappear  in  their  turn, — and  before  it  had 


OUTLINES  OF  ASTRONOMY.  77 

descried  a  small  portion  of  that  abyss  which  separates  us  from 
the  fixed  stars,  the  sun  would  decline  into  a  little  spot,  and  all 
its  splendid  retinue  of  worlds  be  lost  in  the  obscurity  of  distance-; 
— he  would  at  last  shrink  into  a  small  invisible  atom,  and  all 
that  could  be  seen  of  this  vast  magnificent  system,  would  be 
reduced  to  the  glimmering  of  a  little  star.  Why  resist  any 
longer  the  grand  and  interesting  conclusion?  Each  of  those 
stars  may  be  the  token  of  a  system  as  vast  and  as  splendid  as 
the  one  which  we  inhabit.  Worlds  roll  on  in  those  distant 
regions,  and  these  worlds  must  be  the  mansions  of  life  and 
intelligence.  In  yon  gilded  canopy  of  heaven,  we  see  the  bro.id 
aspect  of  the  universe,  where  each  shining  point  presents  us  with 
a  sun,  and  each  sun  with  a  system  of  worlds,  where  the  Divinity 
reigns  in  all  the  grandeur  of  his  attributes,  where  He  peoples 
immensity  with  his  wonders,  and  travels  in  the  greatness  of  his 
strength  through  the  dominions  of  one  vast  unlimited  monarchy. 
The  contemplation  has  no  limits.  If  we  ask  the  number  of  suns 
and  of  systems; — the  unassisted  eye  of  man  can  take  in  a 
thousand,  and  the  best  telescope  which  the  genius  of  man  has 
constructed  can  take  in  80  millions.  But  why  subject  the  do- 
minions of  the  universe  to  the  eye  of  man,  or  to  the  powers  of 
his  genius.  Fancy  may  take  its  flight  far  beyond  the  ken  of  eye 
or  of  telescope.  It  may  expatiate  in  the  outer  regions  of  all  that 
is  visible.  And  shall  we  have  the  boldness  to  say  that  there  is 
nothing  there? — that  the  wonders  of  the  Almighty  are  at  an  end 
because  we  can  no  longer  trace  his  footsteps? — that  his  omnip- 
otence is  exhausted  because  human  art  can  no  longer  follow 
Him  ? — that  the  creative  energy  of  God  has  sunk  into  repose, 
because  the  imagination  is  enfeebled  by  the  magnitude  of  its 
efforts,  and  can  keep  no  longer  on  the  wing  through  those  misty 
tracks  which  shoot  far  beyond  what  eye  hath  seen,  or  the  heart 
of  man  hath  conceived, — which  sweep  endlessly  along,  and  merge 
into  an  awful  and  mysterious  infinity  ?" 

. 

THE    END. 

£>. 


UNIVERSITY  of 

AT 

LOS  ANGELES 
LIBRARY 


4024 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 

Los  Angeles 
This  book  is  DUE  on  the  last  date  stamped  below. 


Form  L9-25m-9,'47(A5618)444 


THE  1TBBARY 

.IFORNU 


G9U 


